The bouncing effects on this sliding menu

Hi, this is my first post here :smiley:

Im currently developing a flash site and found this site really useful to me. Okay, I would like to develope a sliding menu similar to this site: I can see there some bouncing effect there. So anyone of u know the AS of it please show your kindness and provides me a tutorial of it if have any, coz I always wanna learn something instead just ctrl + c and then ctrl + v.