var nvVer = navigator.appVersion;
var nvAgt = navigator.userAgent;
var nvBrowserName  = '';
var nvFullVersion  = 0;
var nvMajorVersion = 0;

// In Internet Explorer, the true version is after "MSIE" in userAgent
if ((verOffset=nvAgt.indexOf("MSIE"))!=-1) {
 nvBrowserName  = "ie";
 nvFullVersion  = parseFloat(nvAgt.substring(verOffset+5));
 nvMajorVersion = parseInt(''+nvFullVersion);
}

// In Firefox, the true version is after "Firefox"
else if ((verOffset=nvAgt.indexOf("Firefox"))!=-1) {
 nvBrowserName  = "ff";
 nvFullVersion  = parseFloat(nvAgt.substring(verOffset+8));
 nvMajorVersion = parseInt(''+nvFullVersion);
}

// Finally, if no name and/or no version detected from userAgent...
if (nvBrowserName.toLowerCase() == nvBrowserName.toUpperCase() || nvFullVersion==0 || nvMajorVersion == 0 ) {
 nvBrowserName  = navigator.appName;
 nvFullVersion  = parseFloat(nvVer);
 nvMajorVersion = parseInt(nvVer);
}