how to add an <All> or <Empty> item to a Clarion FileDrop

gistfile1.vb

! Add the custom row in the reset method

FDBLocation.Reset PROCEDURE
  CODE
  ! Add <All> entry to the queue
  IF Records(SELF.Q) = 0
    Clear(SELF.Q)
    SELF.Q.PRE:DisplayFieldName = '<All>'
    Add(SELF.Q)
  END
  PARENT.Reset

! Then later on when the selection occurs detect if the user has selected our custom row and deal with it.
FDBLocation.TakeNewSelection PROCEDURE
  CODE
  PARENT.TakeNewSelection

  IF SELF.Q.PRE:DisplayFieldName = '<All>'
    Clear(PRE:Record)
    ! Do whatever else you need to do here I guess!
  END