Equivalent to Win32 MessageBox()?

["J. Perkins" <jason@379.com>]

When a fatal error occurs in my game, I'd like to display a message
to the user in a popup window, similar to Win32's MessageBox or
Beos' alert(). Chances are, my application will not have any other
windows open at the time (they will have been closed as part of
the "emergency shutdown"). I don't want to rely on any particular
widget set, so it has to be just straight X. Looking around the web,
it appears that XtPopup/XtPopdown might do what I want, but I'm
having a hard time finding a clear example of how they are used in
this context, and I haven't able to make anything work.

Anyone help me out?

Thanks,
Jason
379