List by file type

[Mike Tuller <realbasic at ce dot anoka dot k12 dot mn dot us>]

I am trying to create an app the will list files by file type that are
located on a volume. I this case, all applications. I am a little confused
as to how I should go about this. Here is what I have so far.

  Dim i As Integer
  Dim apps As FolderItem
  apps = GetFolderItem( "Macintosh HD")
  For i = 1 to apps.count
    if apps.item(i).MacType="APPL" then
      ListBox1.addrow apps.item(i).name
    else
    end
  next

I am not getting anything listed, but I think it is because there are no
applications on the top level. How do I set it to go through all levels?
Also, if someone can tell me if I am headed in the right direction with this
code to be able to find the files.

Thanks,
Mike