Const MDP As String = 'XLD'
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Dim Pass As String
If Application.Intersect(Target, Range('AM:AO')) Is Nothing Then Exit Sub
Pass = Application.InputBox('Saisir Mot de Passe', 'Passworld Area !', Type:=2)
Columns('AM:AO').EntireColumn.Hidden = Not (Pass = MDP)
End Sub