If you get stuck in an X-Windows session there is a way out by pressing
simultaneously Ctrl-Alt-Backspace. Please use this ONLY if you started the X-Windows with startx
or x. Do not use it if you logged on in a terminal that starts
with X-Windows; the X-Windows manager will stop working and people will
not be able to log on after you. In the last case, please contact the
system administrator.