Is it possible to run a movie clip backward smoothly instead of one frame at a
time using
on (press) {
prevFrame ();
}
which requires continual clicking to move the frame backward? I would like
something that would reverse frames continuously with
on (release) {
stop();
}
to end the motion.
I am using Flash 8 and using buttons to control the action.

Well, instead of on(press) you can use a movieClip and use
onClipEvent(enterFrame)

//----------
myClip.onEnterFrame = function(){
this.prevFrame();
}
//---------

Then you'll have to stop it with
//------
myButton.onRelease = function(){
myClip.onEnterFrame = null;
}