var _agt = navigator.userAgent.toLowerCase();

var _win = (_agt.indexOf('win') != -1); // Windows
var _mac = (_agt.indexOf('mac') != -1); // Macintosh

var _ng = (!document.all && document.getElementById);
var _ie = (document.all);
var _ns = (document.layers);

if (_win) {
		if (_ng) {
			with (document) {
					open();
					writeln('<style type="text/css">');
					writeln('@import url(CSS/win_ng.css);');
					writeln('</style>');
					close();
			}
		}
		else if (_ie) {
			with (document) {
					open();
					writeln('<style type="text/css">');
					writeln('@import url(CSS/win_ie.css);');
					writeln('</style>');
					close();
			}
		}
		else if (_ns) {
			with (document) {
					open();
					writeln('<link rel="stylesheet" type="text/css" href="CSS/win_ns.css">');
					close();
			}
		}
}
else if (_mac) {
		if (_ng) {
			with (document) {
					open();
					writeln('<style type="text/css">');
					writeln('@import url(CSS/mac_ng.css);');
					writeln('</style>');
					close();
			}
		}
		else if (_ie) {
			with (document) {
					open();
					writeln('<style type="text/css">');
					writeln('@import url(CSS/mac_ie.css);');
					writeln('</style>');
					close();
			}
		}
		else if (_ns) {
			with (document) {
					open();
					writeln('<link rel="stylesheet" type="text/css" href="CSS/mac_ns.css">');
					close();
			}
		}
}