Shoutbox

I was pressing random buttons on my computer and then a message came up asking me if i wanted to activate a feature, (cant remember what it is called) to keep all my conversations in one window. I want to be able to do this on my other computer aswell. Does anybody know how to do it?

In the plus! prefences enable tabs you must have plus! 3.6 or higher for this to work on your other computer 

Thanks.