判斷pc還是手機打開跳轉到別的網頁

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= 'http://3g.xftz.cn/wpwin/?from=singlemessage&isappinstalled=0'; 
}