JavaScript脚本检测浏览器版本与类型：IE11兼容

<script type="text/javascript">  
var userAgent = navigator.userAgent,     
rMsie = /(msie\s|trident.*rv:)([\w.]+)/,     
rFirefox = /(firefox)\/([\w.]+)/,     
rOpera = /(opera).+version\/([\w.]+)/,     
rChrome = /(chrome)\/([\w.]+)/,     
rSafari = /version\/([\w.]+).*(safari)/;    
var browser;    
var version;    
var ua = userAgent.toLowerCase();    
function uaMatch(ua){    
  var match = rMsie.exec(ua);    
  if(match != null){    
    return { browser : "IE", version : match[2] || "0" };    
  }    
  var match = rFirefox.exec(ua);    
  if (match != null) {    
    return { browser : match[1] || "", version : match[2] || "0" };    
  }    
  var match = rOpera.exec(ua);    
  if (match != null) {    
    return { browser : match[1] || "", version : match[2] || "0" };    
  }    
  var match = rChrome.exec(ua);    
  if (match != null) {    
    return { browser : match[1] || "", version : match[2] || "0" };    
  }    
  var match = rSafari.exec(ua);    
  if (match != null) {    
    return { browser : match[2] || "", version : match[1] || "0" };