If you are not familiar with Akismet, it's a comment-spam management system that's adaptable to almost any application.
BACKUP ANYTHING YOU WILL BE MODIFYING, especially gbook.php and entries.txt ..
Add at your own RISK.
#1 The first thing you do is get a FREE Askimet key HERE.
#2 Next, download the PHP4 or PHP5 (depending on which version php you run) HERE
#3 Ftp the class from step #2 to your guestbook root directory.
#4 Edit your gbook.php and add
above the other requires.require('Akismet.class.php');
Find the code
and replace it with this:addEntry($name,$from,$email,$url,$comments,$isprivate);
Change the ADD_YOUR_API key with the key that you recieve when signing up at Askimet.$WordPressAPIKey = 'ADD_YOUR_API key ';
$MyBlogURL = 'http://www.your_guestbook_url/guestbook/';
$author = $name;
$comment = $comments;
$website = $url;
$akismet = new Akismet($MyBlogURL ,$WordPressAPIKey);
$akismet->setAuthor($author);
$akismet->setAuthorEmail($email);
$akismet->setAuthorURL($website);
$akismet->setContent($comment);
$akismet->setPermalink("http://www.your_guestbook_url/guestbook/'");
if($akismet->isSpam()) {
problem('SPAN Detected.. Shame on you!',0);
} else {
addEntry($name,$from,$email,$url,$comments,$isprivate);
}
Change the www.your_guestbook_url/guestbook/ with the URL to your guestbook..
Again, this worked for me & helps with knocking back the spam.. I am not 100% guaranteeing it will work for you.
Greg