The Monty Project

Hey guys I need some help with the monty project on Alice. I have got it so you can chose the doors but I don't know how to make it so that it either knows which ones you have chosen already or any way to make it work. I need to make it so it shows a monkey after you chose your first door than have the ability to chose another door and that last door decides whether or not you win the car or get another door with a monkey. This is very hard to explain on a forum, Any help would be appreciated. It is the second project in Chapter 9.