Is there a hack to make a pop-up reply window?

I'm thinking about getting VBB forum software and I'm glad to see that hacks are cool with this company (most forum software companies I've seen thus far have been less than interested in this sort of thing.) Anyway, I was wondering if there's a hack for the VBB that creates a pop-up reply window so readers can type a reply to longer threads while still being able to read comments in the thread?

I made a mock-up of what I think this would look like in Netscape (sorry, that's what I got) to give you a better idea of what I'm thinking of, and I circled what I had in mind -- see the attached image to get the jist. Basically, there would be a "pop-up" icon next to "edit", "buddy", and the other items with a thread, and when it's clicked, a reply mini-window pops up (thanks to javascript) which has the username and password pre-loaded and has stripped all the options away except the bare bones stuff. There might also be a "full reply window" button which could transfer the user's text to a new, full-options reply window.

So, does this already exist for VBB, and if not, would it be hard to write?

Thanks!