I need to be able to hide/show categories on index

[jdman321]

http://www.gamepronetwork.com/boards/ is my board.

If you see at the bottom it has hide/show for the birthday section etc...

IT doesn't have to be like that exactly, I just need something that allows users to click a +/- image or a 'Show Category' link near the category name.

I plan on adding a lot of forums and don't want the index to look so 'long' or stretched so this will help a lot.

Another example would be here: http://www.sbdesigning.com/testsb/index.php

Notice the +/- boxes to the left of the categories which make it collapsible.

And if you know how and what I'm talking about could you please share the code and where to put this code? Thanks in advance!

Note: I would LIKE to make it so all categories are hidden by default and can be opened by what I said above.