JS 监听浏览器关闭和刷新
<script language="JavaScript">
window.onbeforeunload = onbeforeunload_handler;
window.onunload = onunload_handler;

function onbeforeunload_handler(){
var warning="离开此页面将退出系统 ！";
return warning;
}

function onunload_handler(){
/* var warning="谢谢光临";
alert(warning); */
　　 Logout();

}

var xmlhttp;
function Logout(){
xmlhttp=null;
if (window.XMLHttpRequest)
{// code for all new browsers
xmlhttp=new XMLHttpRequest();

}
else if (window.ActiveXObject)
{// code for IE5 and IE6
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
alert("你的浏览器是旧的！");
}
if (xmlhttp!=null)
{
xmlhttp.onreadystatechange=state_Change;
xmlhttp.open("GET","edsqc/logout",false);
xmlhttp.send(null);
}
else
{
alert("Your browser does not support XMLHTTP.");
}
}

function state_Change()
{
if (xmlhttp.readyState==4)
{// 4 = "loaded"

if (xmlhttp.status==200)
{// 200 = OK
alert(xmlhttp.responseText);
/* document.write(xmlhttp.responseText); */

}
else
{
alert("Problem retrieving XML data !");
}
}

}
　　


</script>