addLoadEvent

function addLoadEvent(func) { 
var oldonload = window.onload; 
if (typeof window.onload != 'function') { 
window.onload = func; 
} else { 
window.onload = function() { 
oldonload(); 
func(); 


}  

原文地址:https://www.cnblogs.com/dingyuanxin/p/4017652.html