Double post prevention mod????

Hi, i m looking for Double post prevention mod for Invision power board script

Detail about this mod: this mod don't let members double post in a row (I mean without waiting for somebody else to post after him before he can post again) in a targeted thread

I hope somebody can help me in it

 

Basically select the last inserted post and see if it is their id.

SELECT id FROM my_table WHERE post = $POST_ID ORDER BY post_date DESC LIMIT 1;

if($id == $users_id) {
//throw an error that they need to wait.
//Also redisplay their post so they don't lose it.
}

 

I would check the last post made by the user, and see if the text of the new post matches the old post.