在panel的titlebar上放置其他组件

<?xml version="1.0" encoding="utf-8"?>
<mx:Panel  xmlns:mx="http://www.adobe.com/2006/mxml" 
		 layout="vertical" creationComplete="init();"
	removedEffect="Fade" styleName="popUpPanel"   borderColor="#5C5C5C" width="150" height="150">
	<mx:Script>
		<![CDATA[
			import mx.controls.LinkButton;
			import mx.controls.Button;
			import mx.containers.HBox;
			import mx.controls.Image;
			import mx.managers.PopUpManager;
			import mx.controls.Alert;
			
			[Embed(source="add.jpg")]
			private var addIcon:Class;
			
			private function init():void{

				var button:LinkButton = new LinkButton();
				button.setStyle("icon",addIcon);
			//	button.height=16;
				button.addEventListener(MouseEvent.CLICK, buttonClick);

				//Create Hbox to add to title bar
				var titleHbox:HBox = new HBox();
				titleHbox.setStyle("horizontalAlign","center");
				titleHbox.width=this.titleBar.width;
				titleHbox.height=this.titleBar.height;
				//titleHbox.width=200;
				//Add image and button to HBox
				//button.label="add";
				//button.width=45;
				
				titleHbox.addChild(button);
				//Add Hbox with button and image
				titleHbox.label="testadd";
				this.titleBar.addChild(titleHbox);
				//center popup panel
			}
	
			//Function called when button is clicked
			private function buttonClick(event:Event):void{
				Alert.show('Button clicked now closing');
				PopUpManager.removePopUp(this);
			}
		]]>
	</mx:Script>
	
</mx:Panel>