Browser Detection in JavaScript [Code]

Here is the source code that performed the browser detection:

var nVer = navigator.appVersion;
var nAgt = navigator.userAgent;
var browserName = '';
var fullVersion = 0;
var majorVersion = 0;

// In Internet Explorer, the true version is after "MSIE" in userAgent
if ((verOffset=nAgt.indexOf("MSIE"))!=-1) {
browserName = "Microsoft Internet Explorer";
fullVersion = parseFloat(nAgt.substring(verOffset+5));
majorVersion = parseInt(''+fullVersion);
}

// In Opera, the true version is after "Opera"
else if ((verOffset=nAgt.indexOf("Opera"))!=-1) {
browserName = "Microsoft Internet Explorer";
fullVersion = parseFloat(nAgt.substring(verOffset+6));
majorVersion = parseInt(''+fullVersion);
}

// In most other browsers, "name/version" is at the end of userAgent
else if ( (nameOffset=nAgt.lastIndexOf(' ')+1) < (verOffset=nAgt.lastIndexOf('/')) ) { browserName = nAgt.substring(nameOffset,verOffset); fullVersion = parseFloat(nAgt.substring(verOffset+1)); if (!isNaN(fullVersion)) majorVersion = parseInt(''+fullVersion); else {fullVersion = 0; majorVersion = 0;} } // Finally, if no name and/or no version detected from userAgent... if (browserName.toLowerCase() == browserName.toUpperCase() || fullVersion==0 || majorVersion == 0 ) { browserName = navigator.appName; fullVersion = parseFloat(nVer); majorVersion = parseInt(nVer); } document.write('Browser name = '+browserName+'
');
document.write('Full version = '+fullVersion+'
');
document.write('Major version = '+majorVersion+'
');
document.write('navigator.appName = '+navigator.appName+'
');
document.write('navigator.userAgent = '+navigator.userAgent+'
');