PunBB/FluxBB Extension for Private Message Announcements

I have a hobby. I'm an administrator of the forum for Plantarium, a site dedicated to plants of Russia and its neighbors. It's powered by PunBB 1.3.

Someone told me it is hard to notice if there are unread private messages. So I've written an extension to display an announcement, when a new private message arrives. That's how it looks:

Source Code

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

blah blah blah

Download the source code at Gitorious.