Add support for media keys (play, stop, previous and next buttons) in Lubuntu

How one may add support for media keys (play, stop, previous and next buttons) in Lubuntu? Solution provided at http://wiki.lxde.org/en/LXDE:Questions#What_about_the_Play.2C_Stop.2C_Previous_and_Next_buttons.3F is not working.

Modify ~/.config/openbox/lubuntu-rc.xml (it may be copied from /etc/xdg/openbox/rc.xml )

Inside the <keyboard> element add the following to support Clementine (or equivalent to support other music players):

   <keybind key="XF86AudioPlay">
     <action name="Execute">
       <command>clementine --play-pause</command>
     </action>
   </keybind>
   <keybind key="XF86AudioStop">
     <action name="Execute">
       <command>clementine --stop</command>
     </action>
   </keybind>
   <keybind key="XF86AudioNext">
     <action name="Execute">
       <command>clementine --next</command>
     </action>
   </keybind>
   <keybind key="XF86AudioPrev">
     <action name="Execute">
       <command>clementine --previous</command>
     </action>
   </keybind>

and run openbox --reconfigure to reload configuration files.

based on http://wiki.lxde.org/en/LXDE:Questions#What_about_the_Play.2C_Stop.2C_Previous_and_Next_buttons.3F and http://forum.lxde.org/viewtopic.php?f=8&t=1183