Æliens

  dx = spriteB.x - spriteA.x;
  dy = spriteB.y - spriteB.y;
  distance = Math.sqrt(dx*dx + dy*dy);
  if (distance < spriteA.radius + spriteB.radius) {
   ...
  }
  

  var max:Number = ...;
  for (var i:uint; i < max; i++) {
    var objectA = objects[i];
    for (var j:uint = i - 1; j < max; j++) { 
        var objectB = objects[j];
        
 do detection collision(s)
        }
  }