<menuitem priority="750" name="Reboot">
    <icon>general_refresh</icon>
      <callback service="com.nokia.xterm" 
        path="/com/nokia/xterm" 
        interface="com.nokia.xterm" method="run_command" 
        bus="session" autostart="true">
      <argument type="string">/usr/bin/reboot_manual</argument>
    </callback>
  </menuitem>

#!/bin/sh
# gain superuser rights.
if [ `id -u` != 0 ] ; then
    exec sudo gainroot <<EOF
exec sh $0 $*
EOF
exit $?
fi   
# put your code below
reboot