如何实现网页自动判断手机客户端？

将如下代码加在网页标题头部，即可实现手机客户端访问时自动跳转到wap目录下：

<script language="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'; 

} 

</script>