asp drop down menu med mapper

Har flg. script:
<select name="folders">
<%
Dim objFSO
Set objFSO = CreateObject("Scripting.FileSystemObject")
strRootFolder = "rod-folder"
Set objFolder = objFSO.GetFolder(strRootFolder)
Dim objFile
'Now, use a for each...next to loop through the Files collection
For Each objFile in objFolder.Files
    Response.Write ("<option value='" & objFile.Name & "'>" & objFile.Name& "</option><BR>")
Next
%>
</select>


Det viser alle filer i root-folderen, men jeg vil gerne have at det kun
viser MAPPER i rodfolderen....
Nogle bud?