condition in a condition- Help

[xmemx]

I want to add (advertise 1) right after first post, and the rest (advertise 2). How do i do? I tried this and not work.

PHP Code:

<vb:if condition="$post['isfirstshown']">
<vb:if condition="in_array($forum['forumid'], array(1,2,3))">
Show this
<vb:else />
Show this
</vb:if>
</vb:if> 

Please help.