my guestbook is hacked

I did use the search but i could not find helpfull info....
i use this guestbook because it is so damned easy to setup and i am a complete php/mysql noob...

anyway... my guestbook has been hacked and i can't remove the message...
the edit/remove option is black in the admin section.

i did the upgrade patch but that didn't help...
can anyone spare some time to explain me how to remove this message?

the guestbook url is http://www.fraggers.nl/guestbook

thanks for your help![/url]

Post deleted. You need to patch your guestbook. You can find the patch at www.carbonize.co.uk/AG

tnx....