menu déroulant auto incrémenter

Private Sub Worksheet_Change(ByVal Target As Range)
  If Not Intersect([b2:b22], Target) Is Nothing Then
     If IsError(Application.Match(Target.Value, [liste], 0)) Then
        If MsgBox("On ajoute?", vbYesNo) = vbYes Then
           n = [liste].Count
           Sheets("BD").Range("liste")(n).Offset(1, 0) = Target.Value
           Sheets("BD").[liste].Sort key1:=Sheets("BD").Range("liste")
        Else
           Application.Undo
        End If
     End If
   End If
End Sub

Private Sub Worksheet_Change(ByVal Target As Range)
  If Not Intersect([b2:b22], Target) Is Nothing Then
     If IsError(Application.Match(Target.Value, [liste], 0)) Then
           n = [liste].Count
           Sheets("BD").Range("liste")(n).Offset(1, 0) = Target.Value
           Sheets("BD").[liste].Sort key1:=Sheets("BD").Range("liste")
      End If
   End If
End Sub