Corrected an error showing and hiding in (View Pager)

Can you help me correct errors: How the application works: You can specify what you want to read by selecting it with a real marker and what has been specified in (View Pager) opens and if he wants to close one, the mark is canceled. Note: I am a beginner, please explain and I am not good at English. . "
This is an application file black_wolf.aia (8.0 KB)