Wanted: Force first post to contain a link


Active member
I have a "deals and steals" section on my site and I want to force the first post to contain a link to the product or site that the person is letting other users know about in this section.

When submitting the post, I'd like to be have the system display a warning overlay to the user telling them that need to include a link.

It should be sufficient if it checks for any top level domain.

I can't find anything that will do this so I thought I'd ask.