How to judge the micro-letter built-in browser (implemented through the user agent) _javascript tips

In the micro-credit development of the public account, which is a large number of micro-site development, we need to know that the current browser is a micro-mail built-in browser, then how to judge?

User Agent for micro-trust built-in browsers

How to determine the micro-trust built-in browser, first need to obtain a micro-mail built-in browser user agent, after the IPhone on the micro-mail browser detection, its user agent is:

mozilla/5.0 (IPhone; CPU iPhone os 6_1_3 like Mac os X) applewebkit/536.26 (khtml, like Gecko) mobile/10b329 micromessenger/5.0.1

So by identifying Micromessenger this keyword to determine whether the micro-letter built-in browser.

Judging by JavaScript

function Is_weixin () {
var ua = Navigator.userAgent.toLowerCase ();
if (Ua.match (/micromessenger/i) = = "Micromessenger") {return
true;
} else {return
false
;
}}

Judging by PHP

function Is_weixin () { 
if (Strpos ($_server[' http_user_agent '], ' Micromessenger ')!== false) {return
true;< c14/>} return 
false;
}