How do you float a menu like the Apple Store?

Hey guys,

Does anyone know how you would 'float' a menu similar to how they do on in the Apple online store? To clarify, when you start to customize a Mac and you scroll down on the page, the price and options you've selected follow you down on the right.

It is as though it switches from absolute positioning to fixed when the div hits the top of the screen.

Any idea how to recreate that effect?

Regards,
Carson

Web Design

Are you using a specific program for web design?

Check out Dynamic Drive DHTML(dynamic html) & JavaScript code library
Dynamic Drive DHTML scripts- Floating Top Bar script

Beautiful, this link is actually perfect - Dynamic Drive- Dock Content script

Just wish it was a smoother scroll.

Thanks