Can anyone tell me how to actually customize the size of the Chromeless window? I've tried alot of things, but it always end up filling up the entire window

In the part of the tag that is the link to the window:

<a href="#" onclick="mywindow=openIT('window.html',400,300,null,null,'m enu')">

The numbers there are what you change for the size of your screen.

If you're using windows XP, one of the service packs causes chromeless windows to expand to fullscreen.

Actually, it's the I.E 6+ updates, 2 service packs ago, I noticed not only chromeless, but my frameless through codebrain, and several menu scripts I had on sites no longer worked and had to be updated