Choix liste déroulante ou formule dans cellule

Option Explicit
'-----
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Address = "$B$6" Then
     If Target.Value = "OUI" Then
          Application.EnableEvents = False
          With Target.Validation
               .Delete
               .Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, Operator:= _
               xlBetween, Formula1:="=$B$2"
               Target = Range("B2")
          End With
          Application.EnableEvents = True
     End If
     If Target.Value = "" Then
          Application.EnableEvents = False
          With Target.Validation
               .Delete
                .Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, Operator:= _
                xlBetween, Formula1:="=$A$15:$A$16"
          End With
          Application.EnableEvents = True
     End If
 End If
End Sub


Sub sos()
'très utile pour réinitialiser les déclenchements de la macro si on sort accidentellement de la procédure woksheet_change pendant des essais
Application.EnableEvents = True
End Sub