Liste de validation dynamiquement modifiable

Private Sub Worksheet_Change(ByVal Target As Range)
 If Target.Column = 2 And Target.Count = 1 Then
    If Target <> "" Then
      If IsError(Application.Match(Target.Value, [Liste], 0)) Then
        If MsgBox("On ajoute?", vbYesNo) = vbYes Then
          [Liste].End(xlDown).Offset(1, 0) = Target.Value
          Sheets("Liste").[Liste].Sort key1:=Sheets("Liste").Range("A2")
        Else
          Application.Undo
        End If
      End If
    End If
  End If
End Sub