if you put play(); in the first frame, it just tells a movie that's already playing to play. when it reaches the end, there's no new code to execute.

in your new layer, go to the last frame, make it a keyframe if it isn't - since the movie stops, i expect it to be a keyframe. place a button somewhere - if you just want it to just a click anywhere on the movie kind of button just make a transparent button and make it the movie size. also give your button an instance name.

select the keyframe and NOT the button itself, open the actions panel and type the following: