Expanding and Collapsing (PLEASE HELP!!)

[Dave234]

I would like to be able to have a list of words, each with a "+" next to it. If you click on that word (or the "+" sign next to that word), another list of items appear beneath the word.

For example,

+ A

+ B

+ C

+ D

Where you can click on each to get a full list of things that start with either an "A", a "B", a "C", or a "D".

PLEASE if anyone can help me with this, it would be a MAJOR help for my website.