Here is some sample code from MSDN on using the FileSystemObject to enumerate the files inside of a folder (http://msdn.microsoft.com/en-us/library/18b41306(VS.85).aspx):

function ShowFolderFileList(folderspec)
{
   var fso, f, fc, s;
   fso = new ActiveXObject("Scripting.FileSystemObject");
   f = fso.GetFolder(folderspec);
   fc = new Enumerator(f.files);
   s = "";
   for (; !fc.atEnd(); fc.moveNext())
   {
      s += fc.item();
      s += "<br>";
   }
   return(s);
}

something along those lines should do what you want, I'll see if I can cook that down a bit.

- Michael