js判断是否是移动端自动跳转到wap页面代码

<script type="text/javascript">  
        function is_mobile(){   
          var regex_match=/(nokia|iphone|android|motorola|^mot-|softbank|foma|docomo|kddi|up.browser|up.link|htc|dopod|blazer|netfront|helio|hosin|huawei|novarra|CoolPad|webos|techfaith|palmsource|blackberry|alcatel|amoi|ktouch|nexian|samsung|^sam-|s[cg]h|^lge|ericsson|philips|sagem|wellcom|bunjalloo|maui|symbian|smartphone|midp|wap|phone|windows ce|iemobile|^spice|^bird|^zte-|longcos|pantech|gionee|^sie-|portalmmm|jigs browser|hiptop|^benq|haier|^lct|operas*mobi|opera*mini|320x320|240x320|176x220)/i;   
          var u=navigator.userAgent;   
          if (null==u){   
            return true;   
          }   
          var result = regex_match.exec(u);  
          if(null==result){   
            return false  
          }   
          else{   
            return true  
          }   
        }   
        if(is_mobile()){   
          //document.location.href='wap/';
        }else{  
          //document.location.href='pc/';
        }  
    </script>