MC transistions

dear people of kirupa

I have a flash project where I am attaching movie clips onto a blank container movie clip (a basic menu system). Each movie clip, when loaded, has a layer mask tween so the MC appears to grow or tunnel into the page. This works well but I would like the MC to close with a tween when another button in the menu is clicked. i.e I would lke the transision to open and close each MC before opening the next MC.

If any body understands this please can you tell me where I should start looking in the tuts?

Many thanks

Joe