Need help with plugin to allow only one thread in selected forums

[ZiNgA BuRgA]

Ideally, actually, you'd check at the beginning of newthread, telling them they cannot post a new thread.  Perhaps also hide the New Thread button in forums too.

But when helping to code, I just generally try to point out the main "behind the scenes" problems and leave implementation details, including what users may thing, to the person making the thing.