are you asking for vertical menu or horizantal menu?
please clarify this once..
i think you are looking for horizantal menu if it is then
try the bellow url which may meets your requirement
let me know the status
Being that "vertical" was used in the description, and he had mentioned the "more" and "less" links, I am pretty sure he is referring to the vertical menu on the left hand side of the page that has those links to show more or less of the menus.
There are number of tutorials out there for doing this. I recommend jQuery (just because that is what I use :P) because it is widely used and most of the tutorials you find are on jQuery.
I had something similar to it already that I used on some paragraphs, but I made two changes to it and now it can be used the same way you're talking about.