How to start X during bootup as user

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

Hi!

I'm trying to run X from an init script during boot up like this:

#!/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.

Changing from rootonly to anybody makes no difference.
Ok - that's no login shell from there, but...

Thanks in advance,
-Cajus