Forum ID; if conditions, help requested!

[OGZ.Korea]

Hello, I have a problem.

If conditional are very hard for me to understand and to make especially customized if conditionals.

What I'm trying to do is only show the total amount of posts that a member posted in a specific forum / forum id.

Here's my code:
<br />Off Posts: <if condition="in_array($forum['forumid'], array(2,3,4))">$post[posts]</if>

2,3,4 are my forum id's and $post[posts] only show my amount of posts in every forum id not in the specific ones I specified in the if conditional tag.

Please help me, thank you for your time.

Best Regards,
OGZ.Korea