window.onbeforeunload = function (e) {    e = e || window.event;    var y = window.event.clientY;//e.clientY：只有IE8支持    if (y <= 0//点击浏览器或者选项卡的关闭按钮        || y >= Math.max(document.body ? document.body.clientHeight : 0,             document.documentElement ?document.documentElement.clientHeight : 0)//点击任务栏的关闭按钮       ) {        //浏览器关闭之前执行的操作        $.ajax({            type: "POST",                url: "<%=path%>/pages/common/logoutForWebClose.action",            dataType: "text",            async: false,            success: function(data){            alert("closeSuccess");            }        });    }}