X after booting

[Cajus Pollmeier <C.Pollmeier@gmx.net>]

Hi!

I'm trying to make some kind of automatic login for a normal user after 
booting Linux in X.
Made a script "kiosk" and placed it in /etc/init.d, made a link for runlevel 
4 in order to start it when typing "linux 4" at the bootprompt. The script 
contains (shortened) something like that:

#!/bin/bash
while true; do
  su - kiosk -c /usr/X11R6/bin/startx
done 

Starting this manually as root works as expected. While booting I get:
  X: user not authorized to run the X server, aborting.
  var: allowed_users, value: rootonly.
  var: nice_value, value: -10.

Ok - that's no login shell from there, but...
I'm not familiar with that - any ideas? Any docu out there?

Thanks in advance,
-Cajus