Need help programming an item.

[Kyogreblue21]

Hi! I need help programming an item that would allow you quick travel to certain to different regions quickly with a simple choice box

If used, it would show the choice box with each region, some unlocking after certain prerequisites are met:
"Kanto"
"Johto"
"Hoenn"
"Sinnoh"
et cetera
And if selected, would take you the starting town. How could I possibly program it in?

 

[Kyogreblue21]

I've since figured how to make them, I but I can't figure how to close the bag menu once I use the item.