RedAlert

I am a total newbie and got a finished script for my guestbook. Recently I´ve started to get problems with people spamming my guestbook, so I´d like to use this string you´ve written in this thread. But when I tried to copy it into my guestbook it siezed to work at all. Any idea where in the script i should put the string in order to getting it work? The URL to my guestbook is [a href=\"http://www.themovements.com/guestshow.php\" target=\"_blank\"]http://www.themovements.com/guestshow.php[/a] Thanks /Gustaf