Verify and Confirm when Creating a New Thread
 

On a forum I saw some awesome mods that I would like to put on my forum, and they should be pretty simple. Here is a screenshot of what I am referring to:
http://img.photobucket.com/albums/v113/pjkcards/mod.jpg

Basically, when a user creates a new thread, the image verification and the checkbox will come up to confirm the location of where you are posting. You will not be able to make the new thread or modify the title of the thread until you have checked that box.

How would I go about doing this?

Thanks.