播放按钮不起作用

听起来很简单,对吧?显然不是,因为以前对我起过无数次作用的东西现在不起作用了,我不知道为什么,我什么都试过了。这是用于as3的预加载程序。

stop();
this.addEventListener(Event.ENTER_FRAME, loading);

function loading(e:Event):void {
    var total:Number = this.stage.loaderInfo.bytesTotal;
    var loaded:Number = this.stage.loaderInfo.bytesLoaded;

    preloader.bar_mc.gotoAndPlay(Math.floor((loaded/total)*100));

    if (total == loaded) {
        this.removeEventListener(Event.ENTER_FRAME, loading);
        preloader.playLoad.gotoAndPlay(2);
    }
}

preloader.playLoad.playButton.addEventListener(MouseEvent.CLICK, playClick);

function playClick(ev:MouseEvent):void {
    gotoAndPlay(2);
}