Flex中如何给一个按钮添加链接，点击链接打开一个网页呢？

<?xml version="1.0" encoding="utf-8"?>???????? <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" creationComplete="initApp()"???????? layout="absolute" width="278" height="244">???????? <mx:Script>???????? ???? <![CDATA[???????? ???????????? ???????? internal function initApp():void{???????? ????????????var str:String = "<a target='_blank' href='http://sucre.blog.51cto.com/'>paraliseinhell</a>";???????? ???????????? link.htmlText = str;???????? ???????? }???????? ???????????????? ???????? internal function openUrl():void{???????? ???????????? navigateToURL(new URLRequest("http://sucre.blog.51cto.com/"),"_blank");???????? ???????? }???????? ???? ]]>???????? </mx:Script>???????? ???? <mx:Button x="72" y="117" label="paraliseinhell" fontSize="13" id="link2" click="openUrl()"/>???????? ???? <mx:Text id="link" text="paraliseinhell" x="72" y="47" fontSize="13"/>???????? </mx:Application>????