in jwm config documentation
http://www.joewing.net/projects/jwm/config.shtml
as described in the menu section, it's there already, unless you want a one click shutdown
<Exit label="Exit" confirm="false" icon="quit.png"/>
else you need permission to run /sbin/shutdown
I do it in /etc/sudoers
bit dangerous but you could uncomment the wheel line and add yourself to the wheel group
but probably a bit better to be a bit more restrictive than NOPASSWD: ALL
do some homework, sudoers can leave your system open if not treated with respect
is /etc/rc.d/rc.wicd executable (not sure if it is as default) to get the daemon running
<StartupCommand>wicd-client -t</StartupCommand>
will have it started as a tray icon when you log in
I'm using jwm with rox filer
<StartupCommand>rox --rox-session --pinboard=PIN</StartupCommand>
<StartupCommand>udiskie -A -N -t -f rox</StartupCommand>