PopUpManager弹出窗口

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
               xmlns:s="library://ns.adobe.com/flex/spark" 
               xmlns:mx="library://ns.adobe.com/flex/mx"
               minWidth="955" minHeight="600">

    <fx:Script>
        <![CDATA[
            import mx.controls.Label;
            import mx.events.CloseEvent;
            import mx.managers.PopUpManager;
            import spark.components.TitleWindow;
            public var window:TitleWindow = new TitleWindow();
            private var titleWindow:TitleWindow;
            private function buttonClickHandler1(event:MouseEvent):void
            {
                window.title="New Title";
                //PopUpManager.addPopUp(window, this,true);
                PopUpManager.addPopUp(window, this,false);
                PopUpManager.centerPopUp(window);
            }
            
            private function buttonClickHandler2(event:MouseEvent):void
            {
                PopUpManager.removePopUp(window);
                titleWindow = TitleWindow(PopUpManager.createPopUp(this,TitleWindow,true));
                titleWindow.title="New TitileWindow";
                PopUpManager.centerPopUp(titleWindow);
            }
        ]]>
    </fx:Script>
    
    <fx:Declarations>
        <!-- Place non-visual elements (e.g., services, value objects) here -->
    </fx:Declarations>
    <s:VGroup>
        <s:Button id="button1" label="btn1" click="buttonClickHandler1(event)"/>
        <s:Button id="button2" label="btn2" click="buttonClickHandler2(event)"/>
    </s:VGroup>
</s:Application>