Centering dialogs WRT main window (NOT screen)

[Brian Stempel <stempel verinet com>]

Hello,
  I have looked quite a few places for this, and I can't
understand why no one seems to have asked this question
already, so I'll just blurt it out. ;)

  I am trying to center a dialog on top of the parent
main application window, and although I can hack around
with the values of the width & height, x & y positions,
etc., and almost get there, this seems very hackish, and
I was wondering if a more elegant solution existed
within the confines of gtk+ proper. Can anyone help?
Thanks,

	Brian