用JS判断访问跳转手机端和PC端代码

用JS判断访问跳转手机端和PC端代码，仅供参考。

var browser_class = navigator.userAgent;
 var browser_class_name1 = browser_class.match("Mobile");
 var browser_class_name2 = browser_class.match("mobile");
 var location_url = window.location.href;
 if (browser_class_name1 != null || browser_class_name2 != null){
         if (location_url.match("wap") == null){
         window.location.href="http://wap.xxxx.com";
         }
 } else
 {
        if (location_url.match("3g") != null || location_url.match("wap") != null){
        window.location.href="http://3g.xxxx.com";
        }
 }