Private Sub Worksheet_Change(ByVal Target As Range)
Dim entetesColonnes, i As Integer
entetesColonnes = Array("toto1", "toto2", "toto3", "toto4")
For i = LBound(entetesColonnes) To UBound(entetesColonnes)
If Range("A1").Offset(0, i) <> entetesColonnes(i) Then
Application.Undo
Exit Sub
End If
Next i
End Sub