Resetting scroller to the top


I have sliding movie, which contains 3 different MCs. these ease onto the stage depending on the respective buttons clicked. On the stage, the scrolling of any of these movies is controlled by a single scroller. the problem is this: after i’ve scrolled down to read and i click on another button that movie slides in to where the scroller stopped previously. I need to essentially reset the scroller to the top again when another button is clicked. how can i do this?