I'm trying to figure out a good way to approach this.

Basically here's a shot of what's needed. http://stuff.exit42design.com/grabup/475e4d0e25eaf92eefcecdd23af0b0c6.png

It's an alphabetical list of letters down the left column. When you hover over those letters, a list in a block on the right side (with overflow hidden) moves up or down to the letter that's being hovered over. It's sort of reminiscent of the iPhone alphabetical list on the right side of the screen.

I was thinking of creating the letters with anchors to the list as you would see on a normal html page. The question is, how can I tell the content within the div to move up or down? How do I know how far to have it move?