Movie clip button help

Hello im trying to develop a small swf file that the user can control a video that gives the impression of rotation and transparency using arrow buttons. I have a 2 small movie clip files that are currently spread across the timeline exactly 200 frames. the videos are controlled by means of fast forward and rewind this gives the impression of rotation (backwards and forwrds) i have already got the fast forward and rewind function working i would like another set of arrows that control the transparency or alpha of the second movie clip so that when the user presses either an up or down arrow button the transparency goes up or down. Im very new to action script so any basic explanation help would be great. The code for the forward and rewind buttons is as follows (ignore the play function as this button is hidden off stage):


stop();
play_btn.onRelease = function (){
play();
}
pause_btn.onRelease=function(){
stop();
}
forward_btn.onPress=function (){
_root.createEmptyMovieClip("controller_mc",1);
controller_mc.onEnterFrame=function(){
_root.gotoAndStop(_root._currentframe+3);
if (_root._currentframe+3 > _root._totalframes){
_root.gotoAndStop(_root._totalframes);
}
}
}
forward_btn.onRelease=function (){
controller_mc.removeMovieClip();
}
forward_btn.onReleaseOutside=function (){
controller_mc.removeMovieClip();
}
rewind_btn.onPress=function (){
_root.createEmptyMovieClip("controller_mc",1);
controller_mc.onEnterFrame=function(){
_root.gotoAndStop(_root._currentframe-3);
if (_root._currentframe-3 < 1){
_root.gotoAndStop(1);
}
}
}
rewind_btn.onRelease=function (){
controller_mc.removeMovieClip();
}
rewind_btn.onReleaseOutside=function (){
controller_mc.removeMovieClip();
}