/*  Prototype JavaScript framework, version 1.4.0
   *  (c) 2005 Sam Stephenson <sam@conio.net>
   *
   *  THIS FILE IS AUTOMATICALLY GENERATED. When sending patches, please diff
   *  against the source tree, available from the Prototype darcs repository.
   *
   *  Prototype is freely distributable under the terms of an MIT-style license.
   *
   *  For details, see the Prototype web site: http://prototype.conio.net/
   *
  /*--------------------------------------------------------------------------*/
  
  var Prototype = {
    Version: '1.4.0',
    ScriptFragment: '(?:<script.*?>)((\n|\r|.)*?)(?:<\/script>)',
  
    emptyFunction: function() {},
    K: function(x) {return x}
  }
  
  var Class = {
    create: function() {
      return function() {
        this.initialize.apply(this, arguments);
      }
    }
  }
  
  var Abstract = new Object();
  
  Object.extend = function(destination, source) {
    for (property in source) {
      destination[property] = source[property];
    }
    return destination;
  }
  
  Object.inspect = function(object) {
    try {
      if (object == undefined) return 'undefined';
      if (object == null) return 'null';
      return object.inspect ? object.inspect() : object.toString();
    } catch (e) {
      if (e instanceof RangeError) return '...';
      throw e;
    }
  }
  
  Function.prototype.bind = function() {
    var __method = this, args = $$A(arguments), object = args.shift();
    return function() {
      return __method.apply(object, args.concat(A(arguments)));
    }
  }
  
  Function.prototype.bindAsEventListener = function(object) {
    var __method = this;
    return function(event) {
      return __method.call(object, event || window.event);
    }
  }
  
  Object.extend(Number.prototype, {
    toColorPart: function() {
      var digits = this.toString(16);
      if (this < 16) return '0' + digits;
      return digits;
    },
  
    succ: function() {
      return this + 1;
    },
  
    times: function(iterator) {
      $$R(0, this, true).each(iterator);
      return this;
    }
  });
  
  var Try = {
    these: function() {
      var returnValue;
  
      for (var i = 0; i < arguments.length; i++) {
        var lambda = arguments[i];
        try {
          returnValue = lambda();
          break;
        } catch (e) {}
      }
  
      return returnValue;
    }
  }
  
  /*--------------------------------------------------------------------------*/
  
  var PeriodicalExecuter = Class.create();
  PeriodicalExecuter.prototype = {
    initialize: function(callback, frequency) {
      this.callback = callback;
      this.frequency = frequency;
      this.currentlyExecuting = false;
  
      this.registerCallback();
    },
  
    registerCallback: function() {
      setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
    },
  
    onTimerEvent: function() {
      if (!this.currentlyExecuting) {
        try {
          this.currentlyExecuting = true;
          this.callback();
        } finally {
          this.currentlyExecuting = false;
        }
      }
    }
  }
  
  /*--------------------------------------------------------------------------*/
  
  function $() {
    var elements = new Array();
  
    for (var i = 0; i < arguments.length; i++) {
      var element = arguments[i];
      if (typeof element == 'string')
        element = document.getElementById(element);
  
      if (arguments.length == 1)
        return element;
  
      elements.push(element);
    }
  
    return elements;
  }
  Object.extend(String.prototype, {
    stripTags: function() {
      return this.replace(/<\/?[^>]+>/gi, '');
    },
  
    stripScripts: function() {
      return this.replace(new RegExp(Prototype.ScriptFragment, 'img'), '');
    },
  
    extractScripts: function() {
      var matchAll = new RegExp(Prototype.ScriptFragment, 'img');
      var matchOne = new RegExp(Prototype.ScriptFragment, 'im');
      return (this.match(matchAll) || []).map(function(scriptTag) {
        return (scriptTag.match(matchOne) || ['', ''])[1];
      });
    },
  
    evalScripts: function() {
      return this.extractScripts().map(eval);
    },
  
    escapeHTML: function() {
      var div = document.createElement('div');
      var text = document.createTextNode(this);
      div.appendChild(text);
      return div.innerHTML;
    },
  
    unescapeHTML: function() {
      var div = document.createElement('div');
      div.innerHTML = this.stripTags();
      return div.childNodes[0] ? div.childNodes[0].nodeValue : '';
    },
  
    toQueryParams: function() {
      var pairs = this.match(/^\??(.*)/)[1].split('&');
      return pairs.inject({}, function(params, pairString) {
        var pair = pairString.split('=');
        params[pair[0]] = pair[1];
        return params;
      });
    },
  
    toArray: function() {
      return this.split('');
    },
  
    camelize: function() {
      var oStringList = this.split('-');
      if (oStringList.length == 1) return oStringList[0];
  
      var camelizedString = this.indexOf('-') == 0
        ? oStringList[0].charAt(0).toUpperCase() + oStringList[0].substring(1)
        : oStringList[0];
  
      for (var i = 1, len = oStringList.length; i < len; i++) {
        var s = oStringList[i];
        camelizedString += s.charAt(0).toUpperCase() + s.substring(1);
      }
  
      return camelizedString;
    },
  
    inspect: function() {
      return "'" + this.replace('\\', '\\\\').replace("'", '\\\'') + "'";
    }
  });
  
  String.prototype.parseQuery = String.prototype.toQueryParams;
  
  var $$break    = new Object();
  var continue = new Object();
  
  var Enumerable = {
    each: function(iterator) {
      var index = 0;
      try {
        this._each(function(value) {
          try {
            iterator(value, index++);
          } catch (e) {
            if (e != $$continue) throw e;
          }
        });
      } catch (e) {
        if (e != break) throw e;
      }
    },
  
    all: function(iterator) {
      var result = true;
      this.each(function(value, index) {
        result = result && !!(iterator || Prototype.K)(value, index);
        if (!result) throw $$break;
      });
      return result;
    },
  
    any: function(iterator) {
      var result = true;
      this.each(function(value, index) {
        if (result = !!(iterator || Prototype.K)(value, index))
          throw break;
      });
      return result;
    },
  
    collect: function(iterator) {
      var results = [];
      this.each(function(value, index) {
        results.push(iterator(value, index));
      });
      return results;
    },
  
    detect: function (iterator) {
      var result;
      this.each(function(value, index) {
        if (iterator(value, index)) {
          result = value;
          throw $$break;
        }
      });
      return result;
    },
  
    findAll: function(iterator) {
      var results = [];
      this.each(function(value, index) {
        if (iterator(value, index))
          results.push(value);
      });
      return results;
    },
  
    grep: function(pattern, iterator) {
      var results = [];
      this.each(function(value, index) {
        var stringValue = value.toString();
        if (stringValue.match(pattern))
          results.push((iterator || Prototype.K)(value, index));
      })
      return results;
    },
  
    include: function(object) {
      var found = false;
      this.each(function(value) {
        if (value == object) {
          found = true;
          throw break;
        }
      });
      return found;
    },
  
    inject: function(memo, iterator) {
      this.each(function(value, index) {
        memo = iterator(memo, value, index);
      });
      return memo;
    },
  
    invoke: function(method) {
      var args = $$A(arguments).slice(1);
      return this.collect(function(value) {
        return value[method].apply(value, args);
      });
    },
  
    max: function(iterator) {
      var result;
      this.each(function(value, index) {
        value = (iterator || Prototype.K)(value, index);
        if (value >= (result || value))
          result = value;
      });
      return result;
    },
  
    min: function(iterator) {
      var result;
      this.each(function(value, index) {
        value = (iterator || Prototype.K)(value, index);
        if (value <= (result || value))
          result = value;
      });
      return result;
    },
  
    partition: function(iterator) {
      var trues = [], falses = [];
      this.each(function(value, index) {
        ((iterator || Prototype.K)(value, index) ?
          trues : falses).push(value);
      });
      return [trues, falses];
    },
  
    pluck: function(property) {
      var results = [];
      this.each(function(value, index) {
        results.push(value[property]);
      });
      return results;
    },
  
    reject: function(iterator) {
      var results = [];
      this.each(function(value, index) {
        if (!iterator(value, index))
          results.push(value);
      });
      return results;
    },
  
    sortBy: function(iterator) {
      return this.collect(function(value, index) {
        return {value: value, criteria: iterator(value, index)};
      }).sort(function(left, right) {
        var a = left.criteria, b = right.criteria;
        return a < b ? -1 : a > b ? 1 : 0;
      }).pluck('value');
    },
  
    toArray: function() {
      return this.collect(Prototype.K);
    },
  
    zip: function() {
      var iterator = Prototype.K, args = A(arguments);
      if (typeof args.last() == 'function')
        iterator = args.pop();
  
      var collections = [this].concat(args).map($$A);
      return this.map(function(value, index) {
        iterator(value = collections.pluck(index));
        return value;
      });
    },
  
    inspect: function() {
      return '#<Enumerable:' + this.toArray().inspect() + '>';
    }
  }
  
  Object.extend(Enumerable, {
    map:     Enumerable.collect,
    find:    Enumerable.detect,
    select:  Enumerable.findAll,
    member:  Enumerable.include,
    entries: Enumerable.toArray
  });
  var A = Array.from = function(iterable) {
    if (!iterable) return [];
    if (iterable.toArray) {
      return iterable.toArray();
    } else {
      var results = [];
      for (var i = 0; i < iterable.length; i++)
        results.push(iterable[i]);
      return results;
    }
  }
  
  Object.extend(Array.prototype, Enumerable);
  
  Array.prototype._reverse = Array.prototype.reverse;
  
  Object.extend(Array.prototype, {
    _each: function(iterator) {
      for (var i = 0; i < this.length; i++)
        iterator(this[i]);
    },
  
    clear: function() {
      this.length = 0;
      return this;
    },
  
    first: function() {
      return this[0];
    },
  
    last: function() {
      return this[this.length - 1];
    },
  
    compact: function() {
      return this.select(function(value) {
        return value != undefined || value != null;
      });
    },
  
    flatten: function() {
      return this.inject([], function(array, value) {
        return array.concat(value.constructor == Array ?
          value.flatten() : [value]);
      });
    },
  
    without: function() {
      var values = $$A(arguments);
      return this.select(function(value) {
        return !values.include(value);
      });
    },
  
    indexOf: function(object) {
      for (var i = 0; i < this.length; i++)
        if (this[i] == object) return i;
      return -1;
    },
  
    reverse: function(inline) {
      return (inline !== false ? this : this.toArray())._reverse();
    },
  
    shift: function() {
      var result = this[0];
      for (var i = 0; i < this.length - 1; i++)
        this[i] = this[i + 1];
      this.length--;
      return result;
    },
  
    inspect: function() {
      return '[' + this.map(Object.inspect).join(', ') + ']';
    }
  });
  var Hash = {
    _each: function(iterator) {
      for (key in this) {
        var value = this[key];
        if (typeof value == 'function') continue;
  
        var pair = [key, value];
        pair.key = key;
        pair.value = value;
        iterator(pair);
      }
    },
  
    keys: function() {
      return this.pluck('key');
    },
  
    values: function() {
      return this.pluck('value');
    },
  
    merge: function(hash) {
      return H(hash).inject($$H(this), function(mergedHash, pair) {
        mergedHash[pair.key] = pair.value;
        return mergedHash;
      });
    },
  
    toQueryString: function() {
      return this.map(function(pair) {
        return pair.map(encodeURIComponent).join('=');
      }).join('&');
    },
  
    inspect: function() {
      return '#<Hash:{' + this.map(function(pair) {
        return pair.map(Object.inspect).join(': ');
      }).join(', ') + '}>';
    }
  }
  
  function H(object) {
    var hash = Object.extend({}, object || {});
    Object.extend(hash, Enumerable);
    Object.extend(hash, Hash);
    return hash;
  }
  ObjectRange = Class.create();
  Object.extend(ObjectRange.prototype, Enumerable);
  Object.extend(ObjectRange.prototype, {
    initialize: function(start, end, exclusive) {
      this.start = start;
      this.end = end;
      this.exclusive = exclusive;
    },
  
    _each: function(iterator) {
      var value = this.start;
      do {
        iterator(value);
        value = value.succ();
      } while (this.include(value));
    },
  
    include: function(value) {
      if (value < this.start)
        return false;
      if (this.exclusive)
        return value < this.end;
      return value <= this.end;
    }
  });
  
  var $$R = function(start, end, exclusive) {
    return new ObjectRange(start, end, exclusive);
  }
  
  var Ajax = {
    getTransport: function() {
      return Try.these(
        function() {return new ActiveXObject('Msxml2.XMLHTTP')},
        function() {return new ActiveXObject('Microsoft.XMLHTTP')},
        function() {return new XMLHttpRequest()}
      ) || false;
    },
  
    activeRequestCount: 0
  }
  
  Ajax.Responders = {
    responders: [],
  
    _each: function(iterator) {
      this.responders._each(iterator);
    },
  
    register: function(responderToAdd) {
      if (!this.include(responderToAdd))
        this.responders.push(responderToAdd);
    },
  
    unregister: function(responderToRemove) {
      this.responders = this.responders.without(responderToRemove);
    },
  
    dispatch: function(callback, request, transport, json) {
      this.each(function(responder) {
        if (responder[callback] && typeof responder[callback] == 'function') {
          try {
            responder[callback].apply(responder, [request, transport, json]);
          } catch (e) {}
        }
      });
    }
  };
  
  Object.extend(Ajax.Responders, Enumerable);
  
  Ajax.Responders.register({
    onCreate: function() {
      Ajax.activeRequestCount++;
    },
  
    onComplete: function() {
      Ajax.activeRequestCount--;
    }
  });
  
  Ajax.Base = function() {};
  Ajax.Base.prototype = {
    setOptions: function(options) {
      this.options = {
        method:       'post',
        asynchronous: true,
        parameters:   ''
      }
      Object.extend(this.options, options || {});
    },
  
    responseIsSuccess: function() {
      return this.transport.status == undefined
          || this.transport.status == 0
          || (this.transport.status >= 200 && this.transport.status < 300);
    },
  
    responseIsFailure: function() {
      return !this.responseIsSuccess();
    }
  }
  
  Ajax.Request = Class.create();
  Ajax.Request.Events =
    ['Uninitialized', 'Loading', 'Loaded', 'Interactive', 'Complete'];
  
  Ajax.Request.prototype = Object.extend(new Ajax.Base(), {
    initialize: function(url, options) {
      this.transport = Ajax.getTransport();
      this.setOptions(options);
      this.request(url);
    },
  
    request: function(url) {
      var parameters = this.options.parameters || '';
      if (parameters.length > 0) parameters += '&_=';
  
      try {
        this.url = url;
        if (this.options.method == 'get' && parameters.length > 0)
          this.url += (this.url.match(/\?/) ? '&' : '?') + parameters;
  
        Ajax.Responders.dispatch('onCreate', this, this.transport);
  
        this.transport.open(this.options.method, this.url,
          this.options.asynchronous);
  
        if (this.options.asynchronous) {
          this.transport.onreadystatechange = this.onStateChange.bind(this);
          setTimeout((function() {this.respondToReadyState(1)}).bind(this), 10);
        }
  
        this.setRequestHeaders();
  
        var body = this.options.postBody ? this.options.postBody : parameters;
        this.transport.send(this.options.method == 'post' ? body : null);
  
      } catch (e) {
        this.dispatchException(e);
      }
    },
  
    setRequestHeaders: function() {
      var requestHeaders =
        ['X-Requested-With', 'XMLHttpRequest',
         'X-Prototype-Version', Prototype.Version];
  
      if (this.options.method == 'post') {
        requestHeaders.push('Content-type',
          'application/x-www-form-urlencoded');
  
        /* Force "Connection: close" for Mozilla browsers to work around
         * a bug where XMLHttpReqeuest sends an incorrect Content-length
         * header. See Mozilla Bugzilla #246651.
         */
        if (this.transport.overrideMimeType)
          requestHeaders.push('Connection', 'close');
      }
  
      if (this.options.requestHeaders)
        requestHeaders.push.apply(requestHeaders, this.options.requestHeaders);
  
      for (var i = 0; i < requestHeaders.length; i += 2)
        this.transport.setRequestHeader(requestHeaders[i], requestHeaders[i+1]);
    },
  
    onStateChange: function() {
      var readyState = this.transport.readyState;
      if (readyState != 1)
        this.respondToReadyState(this.transport.readyState);
    },
  
    header: function(name) {
      try {
        return this.transport.getResponseHeader(name);
      } catch (e) {}
    },
  
    evalJSON: function() {
      try {
        return eval(this.header('X-JSON'));
      } catch (e) {}
    },
  
    evalResponse: function() {
      try {
        return eval(this.transport.responseText);
      } catch (e) {
        this.dispatchException(e);
      }
    },
  
    respondToReadyState: function(readyState) {
      var event = Ajax.Request.Events[readyState];
      var transport = this.transport, json = this.evalJSON();
  
      if (event == 'Complete') {
        try {
          (this.options['on' + this.transport.status]
           || this.options['on' + (this.responseIsSuccess() ? 'Success' : 'Failure')]
           || Prototype.emptyFunction)(transport, json);
        } catch (e) {
          this.dispatchException(e);
        }
  
        if ((this.header('Content-type') || '').match(/^text\/javascript/i))
          this.evalResponse();
      }
  
      try {
        (this.options['on' + event] || Prototype.emptyFunction)(transport, json);
        Ajax.Responders.dispatch('on' + event, this, transport, json);
      } catch (e) {
        this.dispatchException(e);
      }
  
      /* Avoid memory leak in MSIE: clean up the oncomplete event handler */
      if (event == 'Complete')
        this.transport.onreadystatechange = Prototype.emptyFunction;
    },
  
    dispatchException: function(exception) {
      (this.options.onException || Prototype.emptyFunction)(this, exception);
      Ajax.Responders.dispatch('onException', this, exception);
    }
  });
  
  Ajax.Updater = Class.create();
  
  Object.extend(Object.extend(Ajax.Updater.prototype, Ajax.Request.prototype), {
    initialize: function(container, url, options) {
      this.containers = {
        success: container.success ? $(container.success) : container,
        failure: container.failure ? $(container.failure) :
          (container.success ? null : container)
      }
  
      this.transport = Ajax.getTransport();
      this.setOptions(options);
  
      var onComplete = this.options.onComplete || Prototype.emptyFunction;
      this.options.onComplete = (function(transport, object) {
        this.updateContent();
        onComplete(transport, object);
      }).bind(this);
  
      this.request(url);
    },
  
    updateContent: function() {
      var receiver = this.responseIsSuccess() ?
        this.containers.success : this.containers.failure;
      var response = this.transport.responseText;
  
      if (!this.options.evalScripts)
        response = response.stripScripts();
  
      if (receiver) {
        if (this.options.insertion) {
          new this.options.insertion(receiver, response);
        } else {
          Element.update(receiver, response);
        }
      }
  
      if (this.responseIsSuccess()) {
        if (this.onComplete)
          setTimeout(this.onComplete.bind(this), 10);
      }
    }
  });
  
  Ajax.PeriodicalUpdater = Class.create();
  Ajax.PeriodicalUpdater.prototype = Object.extend(new Ajax.Base(), {
    initialize: function(container, url, options) {
      this.setOptions(options);
      this.onComplete = this.options.onComplete;
  
      this.frequency = (this.options.frequency || 2);
      this.decay = (this.options.decay || 1);
  
      this.updater = {};
      this.container = container;
      this.url = url;
  
      this.start();
    },
  
    start: function() {
      this.options.onComplete = this.updateComplete.bind(this);
      this.onTimerEvent();
    },
  
    stop: function() {
      this.updater.onComplete = undefined;
      clearTimeout(this.timer);
      (this.onComplete || Prototype.emptyFunction).apply(this, arguments);
    },
  
    updateComplete: function(request) {
      if (this.options.decay) {
        this.decay = (request.responseText == this.lastText ?
          this.decay * this.options.decay : 1);
  
        this.lastText = request.responseText;
      }
      this.timer = setTimeout(this.onTimerEvent.bind(this),
        this.decay * this.frequency * 1000);
    },
  
    onTimerEvent: function() {
      this.updater = new Ajax.Updater(this.container, this.url, this.options);
    }
  });
  document.getElementsByClassName = function(className, parentElement) {
    var children = (parentElement || document.body).getElementsByTagName('*');
    return A(children).inject([], function(elements, child) {
      if (child.className.match(new RegExp("(^|\\s)" + className + "(\\s|$$)")))
        elements.push(child);
      return elements;
    });
  }
  
  /*--------------------------------------------------------------------------*/
  
  if (!window.Element) {
    var Element = new Object();
  }
  
  Object.extend(Element, {
    visible: function(element) {
      return element.style.display != 'none';
    },
  
    toggle: function() {
      for (var i = 0; i < arguments.length; i++) {
        var element = $(arguments[i]);
        Element[Element.visible(element) ? 'hide' : 'show'](element);
      }
    },
  
    hide: function() {
      for (var i = 0; i < arguments.length; i++) {
        var element = $(arguments[i]);
        element.style.display = 'none';
      }
    },
  
    show: function() {
      for (var i = 0; i < arguments.length; i++) {
        var element = $(arguments[i]);
        element.style.display = '';
      }
    },
  
    remove: function(element) {
      element = element;
      element.parentNode.removeChild(element);
    },
  
    update: function(element, html) {
      element.innerHTML = html.stripScripts();
      setTimeout(function() {html.evalScripts()}, 10);
    },
  
    getHeight: function(element) {
      element = element;
      return element.offsetHeight;
    },
  
    classNames: function(element) {
      return new Element.ClassNames(element);
    },
  
    hasClassName: function(element, className) {
      if (!(element = element)) return;
      return Element.classNames(element).include(className);
    },
  
    addClassName: function(element, className) {
      if (!(element = element)) return;
      return Element.classNames(element).add(className);
    },
  
    removeClassName: function(element, className) {
      if (!(element = element)) return;
      return Element.classNames(element).remove(className);
    },
  
    // removes whitespace-only text node children
    cleanWhitespace: function(element) {
      element = element;
      for (var i = 0; i < element.childNodes.length; i++) {
        var node = element.childNodes[i];
        if (node.nodeType == 3 && !/\S/.test(node.nodeValue))
          Element.remove(node);
      }
    },
  
    empty: function(element) {
      return element.innerHTML.match(/^\s*/);
    },
  
    scrollTo: function(element) {
      element = element;
      var x = element.x ? element.x : element.offsetLeft,
          y = element.y ? element.y : element.offsetTop;
      window.scrollTo(x, y);
    },
  
    getStyle: function(element, style) {
      element = element;
      var value = element.style[style.camelize()];
      if (!value) {
        if (document.defaultView && document.defaultView.getComputedStyle) {
          var css = document.defaultView.getComputedStyle(element, null);
          value = css ? css.getPropertyValue(style) : null;
        } else if (element.currentStyle) {
          value = element.currentStyle[style.camelize()];
        }
      }
  
      if (window.opera && ['left', 'top', 'right', 'bottom'].include(style))
        if (Element.getStyle(element, 'position') == 'static') value = 'auto';
  
      return value == 'auto' ? null : value;
    },
  
    setStyle: function(element, style) {
      element = element;
      for (name in style)
        element.style[name.camelize()] = style[name];
    },
  
    getDimensions: function(element) {
      element = element;
      if (Element.getStyle(element, 'display') != 'none')
        return {width: element.offsetWidth, height: element.offsetHeight};
  
      // All *Width and *Height properties give 0 on elements with display none,
      // so enable the element temporarily
      var els = element.style;
      var originalVisibility = els.visibility;
      var originalPosition = els.position;
      els.visibility = 'hidden';
      els.position = 'absolute';
      els.display = '';
      var originalWidth = element.clientWidth;
      var originalHeight = element.clientHeight;
      els.display = 'none';
      els.position = originalPosition;
      els.visibility = originalVisibility;
      return {width: originalWidth, height: originalHeight};
    },
  
    makePositioned: function(element) {
      element = element;
      var pos = Element.getStyle(element, 'position');
      if (pos == 'static' || !pos) {
        element._madePositioned = true;
        element.style.position = 'relative';
        // Opera returns the offset relative to the positioning context, when an
        // element is position relative but top and left have not been defined
        if (window.opera) {
          element.style.top = 0;
          element.style.left = 0;
        }
      }
    },
  
    undoPositioned: function(element) {
      element = element;
      if (element._madePositioned) {
        element._madePositioned = undefined;
        element.style.position =
          element.style.top =
          element.style.left =
          element.style.bottom =
          element.style.right = '';
      }
    },
  
    makeClipping: function(element) {
      element = element;
      if (element._overflow) return;
      element._overflow = element.style.overflow;
      if ((Element.getStyle(element, 'overflow') || 'visible') != 'hidden')
        element.style.overflow = 'hidden';
    },
  
    undoClipping: function(element) {
      element = element;
      if (element._overflow) return;
      element.style.overflow = element._overflow;
      element._overflow = undefined;
    }
  });
  
  var Toggle = new Object();
  Toggle.display = Element.toggle;
  
  /*--------------------------------------------------------------------------*/
  
  Abstract.Insertion = function(adjacency) {
    this.adjacency = adjacency;
  }
  
  Abstract.Insertion.prototype = {
    initialize: function(element, content) {
      this.element = element;
      this.content = content.stripScripts();
  
      if (this.adjacency && this.element.insertAdjacentHTML) {
        try {
          this.element.insertAdjacentHTML(this.adjacency, this.content);
        } catch (e) {
          if (this.element.tagName.toLowerCase() == 'tbody') {
            this.insertContent(this.contentFromAnonymousTable());
          } else {
            throw e;
          }
        }
      } else {
        this.range = this.element.ownerDocument.createRange();
        if (this.initializeRange) this.initializeRange();
        this.insertContent([this.range.createContextualFragment(this.content)]);
      }
  
      setTimeout(function() {content.evalScripts()}, 10);
    },
  
    contentFromAnonymousTable: function() {
      var div = document.createElement('div');
      div.innerHTML = '<table><tbody>' + this.content + '</tbody></table>';
      return $$A(div.childNodes[0].childNodes[0].childNodes);
    }
  }
  
  var Insertion = new Object();
  
  Insertion.Before = Class.create();
  Insertion.Before.prototype = Object.extend(new Abstract.Insertion('beforeBegin'), {
    initializeRange: function() {
      this.range.setStartBefore(this.element);
    },
  
    insertContent: function(fragments) {
      fragments.each((function(fragment) {
        this.element.parentNode.insertBefore(fragment, this.element);
      }).bind(this));
    }
  });
  
  Insertion.Top = Class.create();
  Insertion.Top.prototype = Object.extend(new Abstract.Insertion('afterBegin'), {
    initializeRange: function() {
      this.range.selectNodeContents(this.element);
      this.range.collapse(true);
    },
  
    insertContent: function(fragments) {
      fragments.reverse(false).each((function(fragment) {
        this.element.insertBefore(fragment, this.element.firstChild);
      }).bind(this));
    }
  });
  
  Insertion.Bottom = Class.create();
  Insertion.Bottom.prototype = Object.extend(new Abstract.Insertion('beforeEnd'), {
    initializeRange: function() {
      this.range.selectNodeContents(this.element);
      this.range.collapse(this.element);
    },
  
    insertContent: function(fragments) {
      fragments.each((function(fragment) {
        this.element.appendChild(fragment);
      }).bind(this));
    }
  });
  
  Insertion.After = Class.create();
  Insertion.After.prototype = Object.extend(new Abstract.Insertion('afterEnd'), {
    initializeRange: function() {
      this.range.setStartAfter(this.element);
    },
  
    insertContent: function(fragments) {
      fragments.each((function(fragment) {
        this.element.parentNode.insertBefore(fragment,
          this.element.nextSibling);
      }).bind(this));
    }
  });
  
  /*--------------------------------------------------------------------------*/
  
  Element.ClassNames = Class.create();
  Element.ClassNames.prototype = {
    initialize: function(element) {
      this.element = element;
    },
  
    _each: function(iterator) {
      this.element.className.split(/\s+/).select(function(name) {
        return name.length > 0;
      })._each(iterator);
    },
  
    set: function(className) {
      this.element.className = className;
    },
  
    add: function(classNameToAdd) {
      if (this.include(classNameToAdd)) return;
      this.set(this.toArray().concat(classNameToAdd).join(' '));
    },
  
    remove: function(classNameToRemove) {
      if (!this.include(classNameToRemove)) return;
      this.set(this.select(function(className) {
        return className != classNameToRemove;
      }).join(' '));
    },
  
    toString: function() {
      return this.toArray().join(' ');
    }
  }
  
  Object.extend(Element.ClassNames.prototype, Enumerable);
  var Field = {
    clear: function() {
      for (var i = 0; i < arguments.length; i++)
        $(arguments[i]).value = '';
    },
  
    focus: function(element) {
      element.focus();
    },
  
    present: function() {
      for (var i = 0; i < arguments.length; i++)
        if ($(arguments[i]).value == '') return false;
      return true;
    },
  
    select: function(element) {
      element.select();
    },
  
    activate: function(element) {
      element = element;
      element.focus();
      if (element.select)
        element.select();
    }
  }
  
  /*--------------------------------------------------------------------------*/
  
  var Form = {
    serialize: function(form) {
      var elements = Form.getElements(form);
      var queryComponents = new Array();
  
      for (var i = 0; i < elements.length; i++) {
        var queryComponent = Form.Element.serialize(elements[i]);
        if (queryComponent)
          queryComponents.push(queryComponent);
      }
  
      return queryComponents.join('&');
    },
  
    getElements: function(form) {
      form = form;
      var elements = new Array();
  
      for (tagName in Form.Element.Serializers) {
        var tagElements = form.getElementsByTagName(tagName);
        for (var j = 0; j < tagElements.length; j++)
          elements.push(tagElements[j]);
      }
      return elements;
    },
  
    getInputs: function(form, typeName, name) {
      form = form;
      var inputs = form.getElementsByTagName('input');
  
      if (!typeName && !name)
        return inputs;
  
      var matchingInputs = new Array();
      for (var i = 0; i < inputs.length; i++) {
        var input = inputs[i];
        if ((typeName && input.type != typeName) ||
            (name && input.name != name))
          continue;
        matchingInputs.push(input);
      }
  
      return matchingInputs;
    },
  
    disable: function(form) {
      var elements = Form.getElements(form);
      for (var i = 0; i < elements.length; i++) {
        var element = elements[i];
        element.blur();
        element.disabled = 'true';
      }
    },
  
    enable: function(form) {
      var elements = Form.getElements(form);
      for (var i = 0; i < elements.length; i++) {
        var element = elements[i];
        element.disabled = '';
      }
    },
  
    findFirstElement: function(form) {
      return Form.getElements(form).find(function(element) {
        return element.type != 'hidden' && !element.disabled &&
          ['input', 'select', 'textarea'].include(element.tagName.toLowerCase());
      });
    },
  
    focusFirstElement: function(form) {
      Field.activate(Form.findFirstElement(form));
    },
  
    reset: function(form) {
      form.reset();
    }
  }
  
  Form.Element = {
    serialize: function(element) {
      element = element;
      var method = element.tagName.toLowerCase();
      var parameter = Form.Element.Serializers[method](element);
  
      if (parameter) {
        var key = encodeURIComponent(parameter[0]);
        if (key.length == 0) return;
  
        if (parameter[1].constructor != Array)
          parameter[1] = [parameter[1]];
  
        return parameter[1].map(function(value) {
          return key + '=' + encodeURIComponent(value);
        }).join('&');
      }
    },
  
    getValue: function(element) {
      element = element;
      var method = element.tagName.toLowerCase();
      var parameter = Form.Element.Serializers[method](element);
  
      if (parameter)
        return parameter[1];
    }
  }
  
  Form.Element.Serializers = {
    input: function(element) {
      switch (element.type.toLowerCase()) {
        case 'submit':
        case 'hidden':
        case 'password':
        case 'text':
          return Form.Element.Serializers.textarea(element);
        case 'checkbox':
        case 'radio':
          return Form.Element.Serializers.inputSelector(element);
      }
      return false;
    },
  
    inputSelector: function(element) {
      if (element.checked)
        return [element.name, element.value];
    },
  
    textarea: function(element) {
      return [element.name, element.value];
    },
  
    select: function(element) {
      return Form.Element.Serializers[element.type == 'select-one' ?
        'selectOne' : 'selectMany'](element);
    },
  
    selectOne: function(element) {
      var value = '', opt, index = element.selectedIndex;
      if (index >= 0) {
        opt = element.options[index];
        value = opt.value;
        if (!value && !('value' in opt))
          value = opt.text;
      }
      return [element.name, value];
    },
  
    selectMany: function(element) {
      var value = new Array();
      for (var i = 0; i < element.length; i++) {
        var opt = element.options[i];
        if (opt.selected) {
          var optValue = opt.value;
          if (!optValue && !('value' in opt))
            optValue = opt.text;
          value.push(optValue);
        }
      }
      return [element.name, value];
    }
  }
  
  /*--------------------------------------------------------------------------*/
  
  var F = Form.Element.getValue;
  
  /*--------------------------------------------------------------------------*/
  
  Abstract.TimedObserver = function() {}
  Abstract.TimedObserver.prototype = {
    initialize: function(element, frequency, callback) {
      this.frequency = frequency;
      this.element   = element;
      this.callback  = callback;
  
      this.lastValue = this.getValue();
      this.registerCallback();
    },
  
    registerCallback: function() {
      setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
    },
  
    onTimerEvent: function() {
      var value = this.getValue();
      if (this.lastValue != value) {
        this.callback(this.element, value);
        this.lastValue = value;
      }
    }
  }
  
  Form.Element.Observer = Class.create();
  Form.Element.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {
    getValue: function() {
      return Form.Element.getValue(this.element);
    }
  });
  
  Form.Observer = Class.create();
  Form.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {
    getValue: function() {
      return Form.serialize(this.element);
    }
  });
  
  /*--------------------------------------------------------------------------*/
  
  Abstract.EventObserver = function() {}
  Abstract.EventObserver.prototype = {
    initialize: function(element, callback) {
      this.element  = element;
      this.callback = callback;
  
      this.lastValue = this.getValue();
      if (this.element.tagName.toLowerCase() == 'form')
        this.registerFormCallbacks();
      else
        this.registerCallback(this.element);
    },
  
    onElementEvent: function() {
      var value = this.getValue();
      if (this.lastValue != value) {
        this.callback(this.element, value);
        this.lastValue = value;
      }
    },
  
    registerFormCallbacks: function() {
      var elements = Form.getElements(this.element);
      for (var i = 0; i < elements.length; i++)
        this.registerCallback(elements[i]);
    },
  
    registerCallback: function(element) {
      if (element.type) {
        switch (element.type.toLowerCase()) {
          case 'checkbox':
          case 'radio':
            Event.observe(element, 'click', this.onElementEvent.bind(this));
            break;
          case 'password':
          case 'text':
          case 'textarea':
          case 'select-one':
          case 'select-multiple':
            Event.observe(element, 'change', this.onElementEvent.bind(this));
            break;
        }
      }
    }
  }
  
  Form.Element.EventObserver = Class.create();
  Form.Element.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {
    getValue: function() {
      return Form.Element.getValue(this.element);
    }
  });
  
  Form.EventObserver = Class.create();
  Form.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {
    getValue: function() {
      return Form.serialize(this.element);
    }
  });
  if (!window.Event) {
    var Event = new Object();
  }
  
  Object.extend(Event, {
    KEY_BACKSPACE: 8,
    KEY_TAB:       9,
    KEY_RETURN:   13,
    KEY_ESC:      27,
    KEY_LEFT:     37,
    KEY_UP:       38,
    KEY_RIGHT:    39,
    KEY_DOWN:     40,
    KEY_DELETE:   46,
  
    element: function(event) {
      return event.target || event.srcElement;
    },
  
    isLeftClick: function(event) {
      return (((event.which) && (event.which == 1)) ||
              ((event.button) && (event.button == 1)));
    },
  
    pointerX: function(event) {
      return event.pageX || (event.clientX +
        (document.documentElement.scrollLeft || document.body.scrollLeft));
    },
  
    pointerY: function(event) {
      return event.pageY || (event.clientY +
        (document.documentElement.scrollTop || document.body.scrollTop));
    },
  
    stop: function(event) {
      if (event.preventDefault) {
        event.preventDefault();
        event.stopPropagation();
      } else {
        event.returnValue = false;
        event.cancelBubble = true;
      }
    },
  
    // find the first node with the given tagName, starting from the
    // node the event was triggered on; traverses the DOM upwards
    findElement: function(event, tagName) {
      var element = Event.element(event);
      while (element.parentNode && (!element.tagName ||
          (element.tagName.toUpperCase() != tagName.toUpperCase())))
        element = element.parentNode;
      return element;
    },
  
    observers: false,
  
    _observeAndCache: function(element, name, observer, useCapture) {
      if (!this.observers) this.observers = [];
      if (element.addEventListener) {
        this.observers.push([element, name, observer, useCapture]);
        element.addEventListener(name, observer, useCapture);
      } else if (element.attachEvent) {
        this.observers.push([element, name, observer, useCapture]);
        element.attachEvent('on' + name, observer);
      }
    },
  
    unloadCache: function() {
      if (!Event.observers) return;
      for (var i = 0; i < Event.observers.length; i++) {
        Event.stopObserving.apply(this, Event.observers[i]);
        Event.observers[i][0] = null;
      }
      Event.observers = false;
    },
  
    observe: function(element, name, observer, useCapture) {
      var element = element;
      useCapture = useCapture || false;
  
      if (name == 'keypress' &&
          (navigator.appVersion.match(/Konqueror|Safari|KHTML/)
          || element.attachEvent))
        name = 'keydown';
  
      this._observeAndCache(element, name, observer, useCapture);
    },
  
    stopObserving: function(element, name, observer, useCapture) {
      var element = element;
      useCapture = useCapture || false;
  
      if (name == 'keypress' &&
          (navigator.appVersion.match(/Konqueror|Safari|KHTML/)
          || element.detachEvent))
        name = 'keydown';
  
      if (element.removeEventListener) {
        element.removeEventListener(name, observer, useCapture);
      } else if (element.detachEvent) {
        element.detachEvent('on' + name, observer);
      }
    }
  });
  
  /* prevent memory leaks in IE */
  Event.observe(window, 'unload', Event.unloadCache, false);
  var Position = {
    // set to true if needed, warning: firefox performance problems
    // NOT neeeded for page scrolling, only if draggable contained in
    // scrollable elements
    includeScrollOffsets: false,
  
    // must be called before calling withinIncludingScrolloffset, every time the
    // page is scrolled
    prepare: function() {
      this.deltaX =  window.pageXOffset
                  || document.documentElement.scrollLeft
                  || document.body.scrollLeft
                  || 0;
      this.deltaY =  window.pageYOffset
                  || document.documentElement.scrollTop
                  || document.body.scrollTop
                  || 0;
    },
  
    realOffset: function(element) {
      var valueT = 0, valueL = 0;
      do {
        valueT += element.scrollTop  || 0;
        valueL += element.scrollLeft || 0;
        element = element.parentNode;
      } while (element);
      return [valueL, valueT];
    },
  
    cumulativeOffset: function(element) {
      var valueT = 0, valueL = 0;
      do {
        valueT += element.offsetTop  || 0;
        valueL += element.offsetLeft || 0;
        element = element.offsetParent;
      } while (element);
      return [valueL, valueT];
    },
  
    positionedOffset: function(element) {
      var valueT = 0, valueL = 0;
      do {
        valueT += element.offsetTop  || 0;
        valueL += element.offsetLeft || 0;
        element = element.offsetParent;
        if (element) {
          p = Element.getStyle(element, 'position');
          if (p == 'relative' || p == 'absolute') break;
        }
      } while (element);
      return [valueL, valueT];
    },
  
    offsetParent: function(element) {
      if (element.offsetParent) return element.offsetParent;
      if (element == document.body) return element;
  
      while ((element = element.parentNode) && element != document.body)
        if (Element.getStyle(element, 'position') != 'static')
          return element;
  
      return document.body;
    },
  
    // caches x/y coordinate pair to use with overlap
    within: function(element, x, y) {
      if (this.includeScrollOffsets)
        return this.withinIncludingScrolloffsets(element, x, y);
      this.xcomp = x;
      this.ycomp = y;
      this.offset = this.cumulativeOffset(element);
  
      return (y >= this.offset[1] &&
              y <  this.offset[1] + element.offsetHeight &&
              x >= this.offset[0] &&
              x <  this.offset[0] + element.offsetWidth);
    },
  
    withinIncludingScrolloffsets: function(element, x, y) {
      var offsetcache = this.realOffset(element);
  
      this.xcomp = x + offsetcache[0] - this.deltaX;
      this.ycomp = y + offsetcache[1] - this.deltaY;
      this.offset = this.cumulativeOffset(element);
  
      return (this.ycomp >= this.offset[1] &&
              this.ycomp <  this.offset[1] + element.offsetHeight &&
              this.xcomp >= this.offset[0] &&
              this.xcomp <  this.offset[0] + element.offsetWidth);
    },
  
    // within must be called directly before
    overlap: function(mode, element) {
      if (!mode) return 0;
      if (mode == 'vertical')
        return ((this.offset[1] + element.offsetHeight) - this.ycomp) /
          element.offsetHeight;
      if (mode == 'horizontal')
        return ((this.offset[0] + element.offsetWidth) - this.xcomp) /
          element.offsetWidth;
    },
  
    clone: function(source, target) {
      source = source;
      target = target;
      target.style.position = 'absolute';
      var offsets = this.cumulativeOffset(source);
      target.style.top    = offsets[1] + 'px';
      target.style.left   = offsets[0] + 'px';
      target.style.width  = source.offsetWidth + 'px';
      target.style.height = source.offsetHeight + 'px';
    },
  
    page: function(forElement) {
      var valueT = 0, valueL = 0;
  
      var element = forElement;
      do {
        valueT += element.offsetTop  || 0;
        valueL += element.offsetLeft || 0;
  
        // Safari fix
        if (element.offsetParent==document.body)
          if (Element.getStyle(element,'position')=='absolute') break;
  
      } while (element = element.offsetParent);
  
      element = forElement;
      do {
        valueT -= element.scrollTop  || 0;
        valueL -= element.scrollLeft || 0;
      } while (element = element.parentNode);
  
      return [valueL, valueT];
    },
  
    clone: function(source, target) {
      var options = Object.extend({
        setLeft:    true,
        setTop:     true,
        setWidth:   true,
        setHeight:  true,
        offsetTop:  0,
        offsetLeft: 0
      }, arguments[2] || {})
  
      // find page position of source
      source = source;
      var p = Position.page(source);
  
      // find coordinate system to use
      target = target;
      var delta = [0, 0];
      var parent = null;
      // delta [0,0] will do fine with position: fixed elements,
      // position:absolute needs offsetParent deltas
      if (Element.getStyle(target,'position') == 'absolute') {
        parent = Position.offsetParent(target);
        delta = Position.page(parent);
      }
  
      // correct by body offsets (fixes Safari)
      if (parent == document.body) {
        delta[0] -= document.body.offsetLeft;
        delta[1] -= document.body.offsetTop;
      }
  
      // set position
      if(options.setLeft)   target.style.left  = (p[0] - delta[0] + options.offsetLeft) + 'px';
      if(options.setTop)    target.style.top   = (p[1] - delta[1] + options.offsetTop) + 'px';
      if(options.setWidth)  target.style.width = source.offsetWidth + 'px';
      if(options.setHeight) target.style.height = source.offsetHeight + 'px';
    },
  
    absolutize: function(element) {
      element = element;
      if (element.style.position == 'absolute') return;
      Position.prepare();
  
      var offsets = Position.positionedOffset(element);
      var top     = offsets[1];
      var left    = offsets[0];
      var width   = element.clientWidth;
      var height  = element.clientHeight;
  
      element._originalLeft   = left - parseFloat(element.style.left  || 0);
      element._originalTop    = top  - parseFloat(element.style.top || 0);
      element._originalWidth  = element.style.width;
      element._originalHeight = element.style.height;
  
      element.style.position = 'absolute';
      element.style.top    = top + 'px';;
      element.style.left   = left + 'px';;
      element.style.width  = width + 'px';;
      element.style.height = height + 'px';;
    },
  
    relativize: function(element) {
      element = element;
      if (element.style.position == 'relative') return;
      Position.prepare();
  
      element.style.position = 'relative';
      var top  = parseFloat(element.style.top  || 0) - (element._originalTop || 0);
      var left = parseFloat(element.style.left || 0) - (element._originalLeft || 0);
  
      element.style.top    = top + 'px';
      element.style.left   = left + 'px';
      element.style.height = element._originalHeight;
      element.style.width  = element._originalWidth;
    }
  }
  
  // Safari returns margins on body which is incorrect if the child is absolutely
  // positioned.  For performance reasons, redefine Position.cumulativeOffset for
  // KHTML/WebKit only.
  if (/Konqueror|Safari|KHTML/.test(navigator.userAgent)) {
    Position.cumulativeOffset = function(element) {
      var valueT = 0, valueL = 0;
      do {
        valueT += element.offsetTop  || 0;
        valueL += element.offsetLeft || 0;
        if (element.offsetParent == document.body)
          if (Element.getStyle(element, 'position') == 'absolute') break;
  
        element = element.offsetParent;
      } while (element);
  
      return [valueL, valueT];
    }
  }