Looping background animations

Hello Everyone !

I am new to flash catalyst.

I have built a user interface for my application.

What i want is to add animation in the background which plays continuously from start till end of application.

Can i add animation from after effects or flash professional?

But the main thing that i want is to play the animation endlessly in a loop.

Any help would be appreciated. I am stuck here so a rapid response is urgently required.

Thanks.

P.S. Any information about creating a "EXIT" button in catalyst also appreciated. The window should close after pressing the EXIT button.