离开画面时的JavaScript确认提示

window.onbeforeunload = function (evt) { var message = 'Are you sure you want to leave?'; if (typeof evt == 'undefined') { evt = window.event; } if (evt) { evt.returnValue = message; } return message; }

onbeforeunload 事件参考地址

http://msdn.microsoft.com/en-us/library/ms536907(VS.85).aspx