var attention = function (e) {
var confirmationMessage = "修改尚未保存!";
console.log(e.);
(e || window.event).returnValue = confirmationMessage; // Gecko and Trident
return confirmationMessage; // Gecko and WebKit
};
window.addEventListener('beforeunload', attention);
绑定到 window 上时起效,绑定到其他页面元素则不行,例如
var input = document.querySelector('table>input')
input.addEventListener('beforeunload', attention)
http://guoyankun.iteye.com/blog/1765858看看这个吧,能用在三个window,body,frameset这三个元素上。