var browser_name = navigator.appName;
var browser_version = parseFloat(navigator.appVersion);
		
if (browser_name == "Netscape" && browser_version >= 3.0) { 
	roll = 'true';
} else if (browser_name == "Microsoft Internet Explorer" && browser_version >= 4.0) {
	roll = 'false';
} else {
	roll = 'true';
}

if (roll == 'true') {
    document.write('<link rel="stylesheet" type="text/css" href="other.css">');
} else {
	document.write('<link rel="stylesheet" type="text/css" href="ie.css">');
}