installing virtualbox over the web

Not sure if this is the place to put this but hey correct me if I'm wrong.

I want to know how to install virtualbox over the web using ubuntu 12.04 lts desktop

version. Now I am an intermediate ubuntu user which I am pretty comfortable

navigating through terminal prompt but not quite good with materials I need besides

virtualbox and extension pack I have seen a lot of tutorials and each one said

something different which did not work for me. So if anyone has done it please

let me know and I would greatly appreciated if it was broken down but either way

thanks alot in advance.
:)