Sub Worksheet_Change(ByVal Target As Range)
On Error GoTo Fin
If Target.Count > 1 Then Exit Sub
If Not Intersect(Target, Range("D:E")) Is Nothing Then
Application.EnableEvents = False
If Target.Column = 5 And Cells(Target.Row, "D") <> "" Then
Cells(Target.Row, "E") = ""
ElseIf Target.Column = 4 And Cells(Target.Row, "E") <> "" Then
Cells(Target.Row, "D") = ""
End If
End If
Fin:
Application.EnableEvents = True
End Sub