var u = navigator.userAgent, app = navigator.appVersion;
var url = window.location.href;
if (!!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/) || u.indexOf('Android') > -1 || u.indexOf('Linux') > -1) {
    if(url.indexOf('www')> -1){
        url = url.replace(/www/, 'm');
    }else{
        url = url.replace(/:\/\//,'://m.');
    }
  window.location.href="vsm;"
}