Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Count = 1 And Not Application.Intersect(Target, Range("H5:H" & Rows.Count)) Is Nothing Then
question = MsgBox("Voulez-vous mettre à jour la periode de detartrage ?", vbYesNo)
If question = 6 Then
Target.Offset(0, 2).Value = Target.Offset(0, -7).Value
End If
End If
End Sub