browser = navigator.appName;
version = navigator.appVersion;
os = navigator.platform;
ie = "Microsoft Internet Explorer";
nn = "Netscape";
nn6 = "Mozilla";
op = "Opera";

macbr=os.indexOf("Mac");
verbr=navigator.appVersion.indexOf("MSIE 5");

if (browser == nn && macbr=="0" && verbr=="-1") {
        document.write('<link rel=stylesheet type="text/css" href="ss_global.css" title=master>');
} 

else if (browser == ie && macbr=="0" && verbr!="-1" ) {
        document.write('<link rel=stylesheet type="text/css" href="ss_demac.css" title=master>');
} 

else if (browser == nn6 && macbr=="-1" && verbr!="-1" ) {
        document.write('<link rel=stylesheet type="text/css" href="ss_global.css" title=master>');
} 

else if (browser == op && macbr=="0" && verbr!="-1" ) {
        document.write('<link rel=stylesheet type="text/css" href="ss_demac.css" title=master>');
} 

else {
        document.write('<link rel=stylesheet type="text/css" href="ss_global.css" title=master>');
}