Detect Browser name and version using javascript

  var useragent = navigator.userAgent;
 var bName = (useragent.indexOf('Opera') > -1) ? 'Opera' : navigator.appName;
 var pos = useragent.indexOf('MSIE');
 if (pos > -1) {
   bVer = useragent.substring(pos + 5);
   var pos = bVer.indexOf(';');
   var bVer = bVer.substring(0,pos);
 }
 var pos = useragent.indexOf('Opera');
 if (pos > -1)    {
   bVer = useragent.substring(pos + 6);
   var pos = bVer.indexOf(' ');
   var bVer = bVer.substring(0, pos);
 }
 if (bName == "Netscape") {
   var bVer = useragent.substring(8);
   var pos = bVer.indexOf(' ');
   var bVer = bVer.substring(0, pos);
 }
 if (bName == "Netscape" && parseInt(navigator.appVersion) >= 5) {
   var pos = useragent.lastIndexOf('/');
   var bVer = useragent.substring(pos + 1);
 }
 document.writeln('<b>Browser Name: </b>' + bName + '<br>');
 document.writeln('<b>Browser Version: </b>' + bVer + '<br>')