Logging out

[Russell Shaw]

Hi,
In /etc/X11/xorg.conf i have:

Section "ServerFlags"
#   Allow ctrl-alt-backspace
     Option "DontZap" "false"
EndSection

but ctrl-alt-backspace doesn't work.
(Recent xorg server from debian/unstable: Version: 2:1.6.4-2)

How do i log out of X so the xdm screen comes up?