//Confirmation pour l'ajout ou la modification
 public void Confirmer()
 {
     if (nAjout == -1)
     {
         UnAchat.IDOperation = new Model.G_AchatVente(chConnexion).Ajouter(UnAchat.IDVoiture, UnAchat.IDClient, UnAchat.Prix, UnAchat.Date, UnAchat.IDPaiement, UnAchat.Type);
         BcpAchats.Add(new C_AchatVente(UnAchat.IDOperation, UnAchat.IDVoiture, UnAchat.IDClient, UnAchat.Prix, UnAchat.Date, UnAchat.IDPaiement, UnAchat.Type));
     }
     else
     {
         new Model.G_AchatVente(chConnexion).Modifier(UnAchat.IDOperation, UnAchat.IDVoiture, UnAchat.IDClient, UnAchat.Prix, UnAchat.Date, UnAchat.IDPaiement, UnAchat.Type);
         BcpAchats[nAjout] = new C_AchatVente(UnAchat.IDOperation, UnAchat.IDVoiture, UnAchat.IDClient, UnAchat.Prix, UnAchat.Date, UnAchat.IDPaiement, UnAchat.Type);
     }
     ActiverUneFiche = false;
 }