[marat_sa]

Если отключать в настройках automaticaly declare stage, то ошибка:
[Fault] exception, information=ReferenceError: Error #1056: Cannot create property myButton on Main

А если через private var button:MovieClip = this.getChildByName('myButton') as MovieClip;
то:
1061 Call to a possibly undefined method through a reference with static type.