COmplicated question regarding forums

Hi all!

Im about to make my own community with forums and users.
I have been using asp and mysql and Flash MX for this.

Now i want to make a forum. The tricky part is that i would like it to look as in windows Explorer. Like a tree. Every new thread should be a root and all anwsers should be like branches. Did you all understand what i mean? :wink:

Something like this

o
|
—o
|
o
----o
|----o

o=message

Is this possible with Flash and ASP and mySQL?

My second question:
Is it more preferable to use PHP and XML instead of ASP?

I’m rather new at ASP but i have manage so far to create a login, edit user, register user, and view user - .swf that communicates with ASP and mySQL