flex 和swf互相调用

as:
var app:Object;
function setApp(ap:Object):void{
this.app=ap;
}
btn.addEventListener(MouseEvent.CLICK,onClick);
function onClick(event:MouseEvent):void{ 
app.fun(btn.label);
} 
flex:
private function onSwfLoaded(event:Event):void
{
  myloader.addEventListener(Event.COMPLETE, loaderHandler);
}
private function loaderHandler(event:Event):void
{
  Object(myloader.content).setApp(this);
}
public function fun(str:String):void
{
  trace(str);
}