setting child windows to not maximize

["Michael G. Katzmann" <michael industrynumbers com>]

I'm sure this is an FAQ, but I cant find an answer...

How do I prevent child windows from maximizing if the parent
is maximized ?

If I have 'firefox' maximized, and the download window is initiated,
it is maximized to full screen.  I would like it to pop up
as a small box.

Is there a way to differentiate the various windows from a program.
Say the download window (in firefox), from the extentions window, so
I can set a specific size for each in the history ?

Michael