<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
xmlns="*" creationComplete="init()">

<mx:Script>
<![CDATA[

import flash.net.URLRequest;

private function closeApp():void
   {
       var urlString:String = "javascript:self.close()";
       var request:URLRequest = new URLRequest(urlString);
       navigateToURL(request, "_self");
   }

]]>
</mx:Script>

 <mx:LinkButton id="CloseApp" label="Close Application" click="closeApp();"/>

</mx:Application>