AS on buttons

if i have a movie with say 4 buttons, when i press button 1, it plays out ? lets say a box opening from zero to 400 pixels square. i now put a stop command at that point. when the user presses one of the other 3 buttons (any of them, not in any order), i know how to start the movie again to reduce the box back to zero, but how do i then get the movie to jump to the section of movie relating to which ever button’s been pressed ??? anyone ???