javascript onload队列

 1 function addLoadEvent(func){
 2         var oldonload = window.onload;
 3         if (typeof window.onload != ‘function‘) {
 4             window.onload = func;
 5         } else {
 6             window.onload = function(){
 7                 oldonload();
 8                 func();
 9             };
10         }
11     }