Change Default User for SuSE

On OpenSuSE 11.4, the file of /etc/sysconfig/displaymanager contains a line of
"DISPLAYMANAGER_AUTOLOGIN=". The user name specified here is the default user that will do the autologin. It's meaning is explained in the comments as follows.
# Define the user whom should get logged in without request. If string
# is empty, display standard login dialog.