[F]Msg in 'Last Post' for Guests Code Not Working?

Example URL: serened.proboards38.com/index.cgi

Description: I am currently using Mozilla Firefox Version 2.0.0.4 - and this Message in 'Last Post' column for Guests code seems to be not working.

Accessing the main page using Internet Explore (Version 6.0) It seems to be working fine.

Is there a different version of this code somewhere so it works on firefox as well? ...or am I doing something wrong?

Experienced By: Not sure

Code URL: support.proboards.com/index.cgi?board=codedatabase&action=display&n=1&thread=70352&page=1#1127051662

Web Browser: Mozilla Firefox

Code: <script type="text/javascript">
<!--
var cellHTML='Please <a href="?&action=login">Login</a> or <a href="?&action=register">Register</a> to view'

var td=document.getElementsByTagName('td');
for (m=0;m<td.length;m++)
{
if(!document.cookie.match(/\buser=/) && td[m].className=="windowbg2" && td[m].width=="24%" && !td[m].firstChild.innerHTML.match(/(by|on)/))
{
td[m].innerHTML=cellHTML;
}
}
//-->
</script>

Forum URL: serened.proboards38.com