Is there somewhere a desktop independent tool, to logout from an
xsession (and even better: with a suspend and reboot command too :) )?

I tried with lxde-logout in a jwm desktop, but apparently that
does not work.

I also tried a script (found in arch), called oblogout (which
originally came from crunchbang (which was debian based). But that
didn't do the job too.

But probably, i'm doing something wrong (?)

I'd be happy for any suggestion!