Drop Down Menu. Need help

I am creating a 1 scene add-on for a game. I need a drop down menu to call a map. There will be multiple maps and when you choose one from the drop down menu it will display it to the left. I have read so many things on the drop down menu that I think I pretty much have the basics but I need a nudge to finish this off. What I need to know is how do I reference the map sprite? I have the map made. I have it listed in the drop down and now I need to know how to incorporate everything.