Movie clip bounce back

hi, to all the genious’ out there,
i have a movie clip, suppose a ring, and the boundary is set to screen. i have to make the movie clip moving randomly across x and y. i get to work the motion, but i everytime it reaches the boundary i had to position the movie clip in a new location. Is there any way to make it bounce back in an easing way so that, after bouncing back a particular number of pixels, it would continue its random movement? this should happen across all the four boundaries…

great thanks for any help…:sigh: