Message after the first post on every page, or every thread.

[Trickyphillips]

Hello,

I'd like to know of a simple way to display a line of HTML after the first message on every page, or after the first message in every thread. I'm hoping it could easily be done with a simple template modification, like <if condition"$post['var'] = 'data'">HTML</if>.

Can anyone simply point out what I would need to do? Thanks.