Что-то вроде:

Код AS3:
package {
import flash.display.Sprite;
import flash.events.MouseEvent;
import flash.text.TextField;
public class MyButton extends Sprite {
private var _myText:TextField;
public function MyButton(){
super();
this.buttonMode = true;
this.mouseChildren = false;
_myText = new TextField();
addChild(_myText);
_myText.text = "я кнопка"
addEventListener(MouseEvent.MOUSE_OVER, buttonMouseOver);
addEventListener(MouseEvent.MOUSE_OUT, buttonMouseOut);
addEventListener(MouseEvent.MOUSE_DOWN, buttonMouseDown);
addEventListener(MouseEvent.MOUSE_UP, buttonMouseUp);
}
private function buttonMouseOver(e:MouseEvent):void{
_myText.text = "я кнопка"
}
private function buttonMouseOut(e:MouseEvent):void{
_myText.text = "я кнопка и на мне мышь"
}
private function buttonMouseDown(e:MouseEvent):void{
_myText.text = "я кнопка и я нажата"
}
private function buttonMouseUp(e:MouseEvent):void{
_myText.text = "я кнопка"
}
}
}