当关闭标签在IE中起作用但在mozilla和chrome中不起作用时发出警报

Question

window.onbeforeunload = function (event) {
 var message = 'Important: Please check before leave this page.'; if (typeof event == 'undefined') { event = window.event;} if (event) { event.returnValue = message;}
 return message;
 }; 

$(function(){ $("a").not('.cls').click(function () { window.onbeforeunload = null; }); });