It doesnt work, perhaps we are in the wrong place, and we only have to put a code in the forumhome template.
Instead of using $forum[forumid], try using $foruminfo[forumid]. Maybe that will work instead. (Also, try it with and without single quotes around "forumid". I always forget if it needs the quotes in there or not!)
Also, are you editing the correct template? Do this - vboptions > General Settings > Add Template Name in HTML Comments > set to Yes . Then go back to your page and view the source code and you will see the name of the template called around your part of the code.