How to avoid spam?? Please help!

[think_mac_x]

URL: http://www.zappanale.de/forum/
Template(s) used: modified SubOracle
Any and all MODs: Advanced Guestbook and many others
Do you use a port of phpBB: no
Version of phpBB: 2.0.18
Version of PHP: 4.0
Which database server and version: mySQL 4.1
Host: Bit.nl
Did someone install this for you/who: no
Is this an upgrade/from what to what: no
Is this a conversion/from what to what: no
Have you searched for your problem: yes
If so, what terms did you try: spambots, spam, confirmation,...
State the nature of your problem: avoid spam
Do you have a test account for us: probably not needed for solving this problem

I am desperatly looking for a way to avoid spam in my guestbook...
(Advanced Guestbook: http://www.phpbb.com/phpBB/viewtopic.php?t=64412)

In the forum this isnt an issue because no guests are allowed. In the guestbook however I get several spam posts a day! I'm deleting several spam posts every hour now... For a while I could block spam by changing the name of the guestbooks entry.php into another name. But now the spambots must have found a way around this...

I found 2 interesting mods - they seem to be able to avoid spam, but I m pretty sure they will not work on the guestbook without modifying:
http://www.phpbb.com/phpBB/viewtopic.php?t=210055
http://www.phpbb.com/phpBB/viewtopic.php?t=266787

My problem is I don't know any php at all, so I don't know what to do...

What should I do? Please help! many thx in advance

[Anon]

you might have to ask the mod author for help with this one, as they may have integrates visual confirmation with the code