I am wanting to achieve a popup tab type effect without using a motion tween on movie clip.

Basically I have a button, when I rollover it I would like a movie clip (called 'tab') to popup from the bottom with acceleration. When I rollout the tab will decelerate back out of view again.

Kinda like an easing-out/easing-in type effect, but with actionscript.

Any help here would be great.