If is the case...
You want to click the game object and then...flip right? So, you have to use a Mouse Pick Event, to send a event and flip your book.
Basically
1. Make 2 buttons (or game object). The object A and B.
2. Add a fsm to the A and B object and add a state with Mouse Pick Event. Then, is your choise what event you want to emulate the "flip" (Mouse over, donw, up, off).
Sorry my bad english...salutes from Paraguay.