1. Create absolutely positioned images one behind the other
2. On each front image, add Advanced CSS Animator with the following options:
   • TranslateY, "to" = -128
     this means move up 128 pixels.
   • Make sure this is executed onMouseOver
   • Add the Adv CSS Animator behavior again but then onMouseOut with
     TranslateY "to" = 0
     to pull it back down