[AccessD] Walk the controls on a given form

I think I have asked this previously, but if I received an answer then I
misplaced it. Here is exactly what I need.... This is pseudo-code. Don't
expect it to compile!

Sub DumpRowSources ( f as Form )
   'assume the form has already been opened by the calling process
   'I want to walk the controls
   'the only controls of interest are combos or listboxes so I can skip 
   'over all others
   Debug.print f.name
   For Each ctl in f.ControlsCollection     '<--- this is the important part
      If the control is either a listbox or combo-box
         Debug.print ctl.Name & ":"
         Debug.print ctl.RowSource
      End If
   Next
End Sub

TIA!
Arthur