Trying to pause an animation on overlap. Help?

Alright, so I'm already stuck (lol). I'm trying to make a tycoon game somewhat like Shopping Street (http://www.flonga.com/play/shopping-street.htm), or Amuse Park (http://www.freewebarcade.com/game/amuse-park/).

One of the elements I'm trying to emulate is getting the customer to stop and "vanish" for a short while when they overlap with the game shelf. For some reason though, the customer simply goes behind the game shelf, and nothing happens.

Here's the .capx file: http://www.mediafire.com/?f3lktskd552c01b

Thanks for your help.

Nevermind. I still have this problem, but I thought of a different direction I want to take this game, so I'm going to try that instead.

Thanks anyway.