Thread: Stop users registration from outside but they should able to view the ads

Stop users registration from outside but they should able to view the ads

Visitors to this website from outside of country are able to view items for sale, but may not advertise.
The page you are trying to access is not available to visitors outside of the country!

i saw some of classipress website having these features, i'm wonder how they did that? is there any one like to tell me how to do this?