var agt=navigator.userAgent.toLowerCase();
var is_major = parseInt(navigator.appVersion);
var is_nav  = ((agt.indexOf('mozilla')!=-1) && (agt.indexOf('spoofer')==-1) && (agt.indexOf('compatible') == -1) && (agt.indexOf('opera')==-1) && (agt.indexOf('webtv')==-1));
var is_nav4 = (is_nav && (is_major == 4));

if (is_nav4) {
	document.write("<link type='text/css' rel='stylesheet' href='../../styles/ns4.css'>");
}