NN = document.layers; 
IE = document.all; 
isMac = (navigator.appVersion.indexOf("Mac") !=-1); 
isWin = (navigator.appVersion.indexOf("Win")!=-1); 
isLin = (navigator.appVersion.indexOf("Linux") !=-1);
isUnix = (navigator.appVersion.indexOf("X11")!=-1);

if (parseInt(navigator.appVersion.substring(0,1)) >= 4) {
		 if (NN && isWin) {cs="itss_main_win_ns.css";}
	else if (NN && isMac) {cs="itss_main_mac_ns.css";}
	else if (isLin) {cs="itss_main_lin.css";}
	else if (isUnix) {cs="itss_main_unix.css";}
	else if (IE && isWin) {cs="itss_main_win_ie.css";}
	else if (IE && isMac) {cs="itss_main_mac_ie.css";}
	else {cs="itss_main_other.css";}
} else {cs="itss_main_other.css";}
document.write('<link rel=stylesheet type="text/css" href="http://www.stanford.edu/dept/itss/styles2002/' + cs + '">');