xdm setup

[David List <david@davidlist.dk>]

I'm looking into the graphical login setup on my newly installed Debian
Woody. I'm used to having a line near the end of /etc/inittab that says
how the graphical login screen should behave, for instance:

# Run XDM in run level 5
x:5:respawn:/usr/bin/X11/xdm -nodaemon

I don't see this in the default Debian /etc/inittab file (I chose xdm as
my display manager during installation).
In which file(s) is it decided how the login screen should act, on a
Debian system?

Best regards,
David List