Ok you say you have 2 frames lets call them start and end so we know which ones we are refering to.

1. with start on view in km click on + and then click on add copy of frame ( so the new copy becomes frame 2 - put a stop on this frame.

2. with end on view put a stop on this frame.

3. with start in view click + the add copy of frame to end ( this will become frame 4 )

so now you have 4 frames

frame 1 = start
frame 2 = start(with a stop on the frame)
frame 3 = end (with a stop on the frame)
frame 4 = start

now put a button1 on frame 2, and in actions click on Start movie ( this will start the morph and stop on frame 3 at the end of the morph.

now put a button2 on frame 3, and in actions click on Start movie ( this will start the reverse morph and stop on frame 2.

Hope that is all clear.