Another question on Screeen Navigation using lua+corona

I keep loosing days and days of work because I can’t understand the steps needed for navigate between screens.
I saw and tested your demos (tabBar app and other demos) but still a lot of confusion is around here.
I prepared a 3 screen app that have only two buttons that should go to the next and previous screen, but cannot make it run properly.
I think the issue is in the routine that run’s the event associated with the buttons.
I’ll appreciate very much if someone could unlock this personal problem.

The project can be found here
http://hotfile.com/dl/103753307/2b2d283/test.zip.html

Thanks in advance.

[import]uid: 13114 topic_id: 6413 reply_id: 306413[/import]

Problem solved using director solution by Ricardo Rauber [import]uid: 13114 topic_id: 6413 reply_id: 22287[/import]