[squidsk]

Why not just use the post count that is attached to the users profile, which will usually be accessible from, or made accessible from all locations. It will be a much faster query because you aren't going through the entire post table to search for things, and likely won't need any additional queries to make it work and it will automatically exclude all forums that don't contribute to post count.

If you really want to query the post table then use this code as it's better than what you have:

$grabposts = mysql_query_first("COUNT * AS posts FROM post WHERE userid = '" . $userid . "' AND forumid NOT IN (forumid1, forumid2, . . . .)");
$numposts = $grabposts['posts'];
$postsamount = number_format($numposts);