如何在用户关闭IE时执行session.abandon事件？

 1<script language="javascript">   
 2function window.onbeforeunload()   
 3{   
 4if(event.clientX>document.body.clientWidth&&event.clientY<0 ¦ &brvbarevent.altKey)   
 5{   
 6var xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");   
 7xmlhttp.open("GET","sessionEnd.asp",false);   
 8xmlhttp.send();   
 9}   
10}   
11</script>