Actionscript when playing the movie backwards

hey y’all,

i was thinking if it is possible to assign an actionscript to the timeline when the movie is playing backwards. i mean, the movie would not pick up the script on its way to a specific frame but only when it is moving backwards.

im aware i could just go around this problem by just copying and pasting the frames and then reversing them, but this would make the file size bigger.

thanks