var isIE = document.all?true:false;
var isNS = document.all?true:false;
if (isIE) {document.write("<link rel='stylesheet' href='navie.css'>");}
else if (isNS) {document.write("<link rel='stylesheet' href='navie.css'>");}
else {document.write("<link rel='stylesheet' href='navff.css'>");}