Web page-opening a new window

My first question, I hope I am in the correct section:-
I have a web page that needs regular STOP-PRESS updates that are most convenient with a new (small) window. I use the following code (in page index.html) which works fine in IE5, NS6.2, Opera6+ & Moz. but the link is dead in NS4.7, other javascript on the site work ok in NS4.7

STOP PRESS

I still get about 5% of my visitors use NS4.7 so I don’t want to ignore them.

I’ve searched the web and scanned a pile of books to no avail. Help please!

Ray