Display contents of subfolders /subdirectroies

Hi All,

I'm new to AIR so maybe a dumb question.  I'm using getDirectoryListing() to get the files/folders within a given directory, but I would like to be able to list the contents within subfolders / subdirectories.  I can't seem to find any documentation or tutorials about this.  Any help greatly appreciated!!

This is my code so far, launched from a mouse event:

function directorySelected(event:Event):void{
     directory = event.target as File;
     var files:Array = directory.getDirectoryListing();
     fileNamesDirty.length = 0;
         for(var i:uint = 0; i < files.length; i++){
                fileNamesDirty.push(files[i].nativePath);

               //Works great, now how do I list files in subdirectories?!
         }
}

Once I figure out how to do this I will be able to take-over the world with my applications MUAHAHHAHHAHA!!!!!!  .. sorry it's late ...