gdm v. kdm v. xdm

[John DeCarlo]

Hello,

I recently installed kubuntu-desktop and the install asked a question
about which should be the default manager, but I forget what I
answered (duh).

Anyway, now it won't start the graphical login.  The message is that
xdm is not the default manager, so it won't start.

How should I fix this problem?  I would prefer a graphical login that
allowed me to select whether to use Gnome or KDE.

Thanks.

-- 
John DeCarlo, My Views Are My Own