flex中弹出确认对话框

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" backgroundColor="black" layout="horizontal">
    <mx:Script>
        <![CDATA[
            import mx.events.CloseEvent;
            import mx.controls.Alert;
            public function deleteConfirm():void{
                Alert.yesLabel = 'yes';
                Alert.noLabel = 'no';
                Alert.cancelLabel = 'cancel';
                Alert.show('确认要删除吗','info',1|2|8,this,back);
            }
            public function back(event:CloseEvent):void{
                if(event.detail==Alert.YES){
                    Alert.show('削除しました');
                }
            }
        ]]>
    </mx:Script>
    <mx:Button label="削除" click="deleteConfirm()"/>
</mx:Application>

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" backgroundColor="black" layout="horizontal">
	<mx:Script>
		<![CDATA[
			import mx.events.CloseEvent;
			import mx.controls.Alert;
			public function deleteConfirm():void{
				Alert.yesLabel = 'yes';
				Alert.noLabel = 'no';
				Alert.cancelLabel = 'cancel';
				Alert.show('确认要删除吗','info',1|2|8,this,back);	
			}
			public function back(event:CloseEvent):void{
				if(event.detail==Alert.YES){
					Alert.show('削除しました');
				}
			}
		]]>
	</mx:Script>
	<mx:Button label="削除" click="deleteConfirm()"/>
</mx:Application>