Roguelike: room generation sourcecode

A few people (hi, /r/roguelikes!) have asked if I'd share my roguelike source code, or at least some of it. As a Flash dev I know I'd be really excited to see how other Flash devs are handling roguelike development, so I figured it's only fair to get mine out there. I'm hoping some gurus out there will tell me if I'm doing this wrong, and point me in the right direction, it's all a learning process!

OK, so anyway, the first thing I'm posting is a highly simplified version of my room generation code, that shows a random single room being built, and a character dropped on to a valid random square. I've also stuck it on an external Pastebin link rather than an embedded one, as this code has long descriptive comments on that freak out a bit when they're stuffed into a thin blog format.

Feedback would be appreciated!

http://pastebin.com/BBPpGPBz