I am creating a side scrolling platform game using the book "Flash Game University" by Gary Rosenzweig.

I have my player character called "hero".
My spring object is a movie clip with 3 frames each with a different label: start, down, up. When my hero collides with the spring I want to programmatically instruct the spring to go to the second frame and start to play. I then want the spring to make me jump in the air 2-3 times higher than my normal jump can do. The third piece is how to make the collision occur only when the hero jumps on the top of the spring and not by running into it from the sides?

Does anyone have a solution?

Thanks,
Alex