Image-entertainment's navigation q

First Post! It’s about time…I’ve looked at this forum for great answers to my problems.

So I was looking around sites for navigation, and came across this:

http://www.image-entertainment.com/

I really like the way the menu with the four to five movies that scroll to the left and when hovering over them, the one you chose expands, pushes the other ones to the right of it away, and shows a description, stopping the movement.

I’m thinking that this is partially the same concept as the infinite scroller, but how did they enable the object to “push” the other objects away? tween class?

http://www.kirupa.com/developer/mx/infinite.htm

Thanks! I’m gonna try and figure this out as well.