<script type="text/javascript"> 
// 说明 ： 通过 Javascript 实现的 CSS 浏览器选择符（CSS Browser Selector） 
// 整理 ： CodeBit.cn ( http://www.codebit.cn ) 
 
// CSS Browser Selector   v0.2.5 
// Documentation:         http://rafael.adm.br/css_browser_selector 
// License:               http://creativecommons.org/licenses/by/2.5/ 
// Author:                Rafael Lima (http://rafael.adm.br) 
// Contributors:          http://rafael.adm.br/css_browser_selector#contributors 
var css_browser_selector = function() { 
    var  
        ua=navigator.userAgent.toLowerCase(), 
        is=function(t){ return ua.indexOf(t) != -1; }, 
        h=document.getElementsByTagName('html')[0], 
        b=(!(/opera|webtv/i.test(ua))&&/msie (\d)/.test(ua))?('ie ie'+RegExp.$1):is('gecko/')? 'gecko':is('opera/9')?'opera opera9':/opera (\d)/.test(ua)?'opera opera'+RegExp.$1:is('konqueror')?'konqueror':is('applewebkit/')?'webkit safari':is('mozilla/')?'gecko':'', 
        os=(is('x11')||is('linux'))?' linux':is('mac')?' mac':is('win')?' win':''; 
    var c=b+os+' js'; 
    h.className += h.className?' '+c:c; 
}(); 
</script>