document.write not working in NS

[pnj]

here is my code.
this works in IE and not in NS4.7.

<script language='JavaScript'>
<!--
var ns = (navigator.appName == 'Netscape');
var ie = (navigator.appName == 'Microsoft Internet Explorer');
//var disnavsize='';
var d = window.document;

if(ns) {disnavsize='10'};
if(ie) {disnavsize='9'};

document.write("<style type='text/css'>");

document.write('A.DisNav {color:#666666;font-weight: bold; font-size:' + disnavsize + 'px; text-decoration: none; font-family: Arial, helvetica;}');
document.write('A.DisNav:hover {color:#9ccc99;}');
document.write('</style>');
-->

</script>

<a class=DisNav href="#"><br>testing</a>


the style sheet gets ignored completly in NS

any suggestions?

thanks