// link to appropriate css file
var isMac = false;

if (navigator.platform && (navigator.platform.indexOf('Mac')) > -1) {
	//mac users
	isMac = true;
    document.write('<link href="http://www.ast-ss.com/css/mac.css" rel="stylesheet" type="text/css">');
} 
else {
	//windows or unix
	if (navigator.appName.indexOf('Microsoft') > -1) {
		//explorer
		document.write('<link href="http://www.ast-ss.com/css/win_ie.css" rel="stylesheet" type="text/css">');
	} 
	else {
	//netscape
		document.write('<link href="http://www.ast-ss.com/css/win_ns.css" rel="stylesheet" type="text/css">');
	}
}