在基于Gecko的浏览器中检测窗口关闭事件

Question

如何在用户按下Alt + F4或在基于Gecko的浏览器中使用javascript window.close（）来检测窗口关闭事件？

Answer 1

window.onbeforeunload =function(){return '';} 

Answer 2

.......

window.onunload = function(){ 
    alert('I am getting closed !!'); 
};