>to create a popup window you have to insert the code into the onload event, this way it is guarenteed to pop up. i forget the exact code but it is also possible to specify the size of the window and what menu items appear as well if that is any use to you.
>~M

See here for IE parameters
http://msdn.microsoft.com/workshop/author/dhtml/reference/methods/open_0.asp

For Netscape (3) parameters:
http://home.netscape.com/eng/mozilla/3.0/handbook/javascript/ref_m-q.htm#177627

I've given you both so you can see that while similar, there are some differences, so you may need to look at various sets of documentation to ensure reasonable cross-browser compatibility.