判断当前的浏览器是pc还是移动设备，是微信端还是自带其它浏览器。

<script type="text/javascript">
    var mobileAgent = new Array("iphone", "ipod", "ipad", "android", "mobile", "blackberry", "webos", "incognito", "webmate", "bada", "nokia", "lg", "ucweb", "skyfire");
    var browser = navigator.userAgent.toLowerCase(); 
    var isMobile = false; 
    for (var i=0; i<mobileAgent.length; i++){ 
        if (browser.indexOf(mobileAgent[i])!=-1){
            isMobile = true; 
            var ua = navigator.userAgent.toLowerCase();
            var isWeixin = ua.indexOf('micromessenger') != -1;
            if (isWeixin) {
                location.href = 'wap.xxx.com';  //微信跳转指定链接
            }else{
                location.href = 'm.xxx.com';  //其它跳转指定链接
            }
            break; 
        }
    } 
</script>