function add_browser_class() {
	var nVer = navigator.appVersion;
	var nAgt = navigator.userAgent;
	var browserName  = navigator.appName;
	var fullVersion  = ''+parseFloat(navigator.appVersion); 
	var majorVersion = parseInt(navigator.appVersion,10);
	var nameOffset,verOffset,ix;
	
	// In MSIE, the true version is after "MSIE" in userAgent
	if ((verOffset=nAgt.indexOf("MSIE"))!=-1) {
		browserName = "Microsoft Internet Explorer";
		fullVersion = nAgt.substring(verOffset+5);
	}
	// In Opera, the true version is after "Opera" 
	else if ((verOffset=nAgt.indexOf("Opera"))!=-1) {
		browserName = "Opera";
		fullVersion = nAgt.substring(verOffset+6);
	}
	// In Chrome, the true version is after "Chrome" 
	else if ((verOffset=nAgt.indexOf("Chrome"))!=-1) {
		browserName = "Chrome";
		fullVersion = nAgt.substring(verOffset+7);
	}
	// In Safari, the true version is after "Safari" 
	else if ((verOffset=nAgt.indexOf("Safari"))!=-1) {
		browserName = "Safari";
		fullVersion = nAgt.substring(verOffset+7);
	}
	// In Firefox, the true version is after "Firefox" 
	else if ((verOffset=nAgt.indexOf("Firefox"))!=-1) {
		browserName = "Firefox";
		fullVersion = nAgt.substring(verOffset+8);
	}
	// 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 = nAgt.substring(verOffset+1);
		if (browserName.toLowerCase()==browserName.toUpperCase()) {
			browserName = navigator.appName;
		}
	}
	// trim the fullVersion string at semicolon/space if present
	if ((ix=fullVersion.indexOf(";"))!=-1) fullVersion=fullVersion.substring(0,ix);
	if ((ix=fullVersion.indexOf(" "))!=-1) fullVersion=fullVersion.substring(0,ix);
	
	majorVersion = parseInt(''+fullVersion,10);
	if (isNaN(majorVersion)) {
		fullVersion  = ''+parseFloat(navigator.appVersion); 
		majorVersion = parseInt(navigator.appVersion,10);
	}
	
	document.body.className += " " + browserName + " " + browserName + majorVersion;
}