[Flex] Coding Note

Using Sprite in flex:
class needs to be inherited from "SpriteVisualElement", not "Sprite"

for each and for key:
for each : get value
var obj:Object = {x:10, y:20};
for each (var num in obj)
{
   trace(num); //get 10, 20
}

for (var key:String in obj)
{
     trace(obj[key]);//get 10, 20. but key is x, y
}