两种方法实现在HTML页面加载完毕后运行某个js

 1 <script type="text/javascript"> 
 2 
 3 window.onload=function(){ 
 4 
 5 var userName="xiaoming"; 
 6 
 7 alert(userName); 
 8 } 
 9 
10 </script> 

<script type="text/javascript"> 

$(document).ready(function(){ 

var userName="xiaoming"; 

alert(userName); 
}); 

</script> 

$(function(){ 
var userName="xiaoming"; 
alert(userName); 
});