Reversing Flash Movie to specific point

Hi, maybe there’s an easier way to do this than what I’m trying. I’m want to have my flash movie reverse what was previously loaded before it moves on to the next part, after someone pushes a specific button. You see this in alot of cool Flash sites as transitions that play in reverse what was just loaded to make it seem like it unloaded the previous animation. I hope I’m being clear here. I just want it to play the animation, then before someone goes to the desired keyframe, it plays in reverse what was just loaded.

I’ve tried using this…but it rewinds the whole movie instead of stopping at a specific keyframe:

this.onEnterFrame = function(){
if(rewind == true){
this.onRelease = function(){
rewind = true;

Help please…muchas gracias!!!:ne: