动态调用CSS文件的JS代码

<script type="text/javascript" language="javascript"> 
var _sn = ["df/common", "df/home2010"]; 
var _su = "http://www.jb51.net/skin/"; 
var Swidth = screen.width; var _se, _st; 
for (i in _sn) { 
_se = document.createElement("link"); 
_se.type = "text/css"; 
_se.rel = "stylesheet"; 
if (Swidth >= 1280) { 
_st = _su + _sn[i] + ".w.css"; 
} else { 
_st = _su + _sn[i] + ".css"; 
} 
_se.href = _st; 
document.getElementsByTagName("head")[0].appendChild(_se); 
} 
</script>