Help with MIT App Inventor +K

[7-11_Slurpee]

Sitting in my intro to mobile app class we're supposed to make a "flipping" app where it cycles between 3 different images. This is the tutorial where it flips between 2 but I can't figure out how to add the third image to cycle it.

http://turing.cs.trincoll.edu/~ram/cpsc110-f11/notes/coinflip.html

I know its probably simple, but im lost. Any help for +K

 

[Hause]

what language are you using? I know that java and c# have random class functions to get random numbers within a certain range.