function useCSS()
{
	var ns4 = ((navigator.appName == "Netscape") && (parseInt(navigator.appVersion) >= 4 ));

	if (ns4){
		 document.write('<link rel="stylesheet" type="text/css" href="styles/main_nav.css">');
		}
	else {
		 document.write('<link rel="stylesheet" type="text/css" href="styles/main.css">');
		}
}

useCSS();