How to set "open" window to select paths and specific file types

Hey all,

I have the normal ‘Windows’ window that opens up in my Flash app. I can get my app to get any file.

How can I make that window select a path instead of a file? Also, I want to display the contents of that directory into a listbox, which I can do, but I don’t know how to display only certain filetypes from the selected directory.

Thanks.