给Flex的PopUpManager显示控件添加特效

PopUpEffect.as
package
{
import flash.display.DisplayObject;

import mx.core.IFlexDisplayObject;
import mx.effects.Blur;
import mx.events.TweenEvent;
import mx.managers.PopUpManager;

public class PopUpEffect
{

public function PopUpEffect()
{
}
public static function Show(control:IFlexDisplayObject,parent:DisplayObject,modal:Boolean=true):void
{
var mShowEffect:Blur=new Blur();
mShowEffect.blurXfrom=255;
mShowEffect.blurYfrom=255;
mShowEffect.blurXTo=0;
mShowEffect.blurYTo=0;
mShowEffect.target= control;
mShowEffect.duration=300;
PopUpManager.addPopUp(control,parent,modal);
PopUpManager.centerPopUp(control);
mShowEffect.play();

}
public static function Hide(control:IFlexDisplayObject):void
{

var mHideEffect:Blur=new Blur();
mHideEffect.blurXfrom=0;
mHideEffect.blurYfrom=0;
mHideEffect.blurXTo=255;
mHideEffect.blurYTo=255;
mHideEffect.addEventListener(TweenEvent.TWEEN_END,function(){
PopUpManager.removePopUp(control);
});
mHideEffect.duration=300;
mHideEffect.target=control;
mHideEffect.play();
}
}
}
main.mxml
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
    <mx:Script>
        <!--[CDATA[
            import PopUpEffect;
        ]]>
    </mx:Script>
    <mx:Button label="登陆" horizontalCenter="0" verticalCenter="0">