// JScript 文件
function loadScript (url, callback) { 
var script = document.createElement('script'); 
script.type = 'text/javascript';
script.charset="gb2312";
/* should be application/javascript 
* http://www.rfc-editor.org/rfc/rfc4329.txt 
* http://connect.microsoft.com/IE/feedback/ViewFeedback.aspx?FeedbackID=84613 
*/ 
if (callback) 
script.onload = script.onreadystatechange = function() { 
if (script.readyState && script.readyState != 'loaded' && script.readyState != 'complete') 
return; 
script.onreadystatechange = script.onload = null; 
callback(); 
}; 
script.src = url; 
document.getElementsByTagName('head')[0].appendChild (script); 
}