public void Modifier()
 {
     if (AchatSelectionnee != null)
     {
         C_AchatVente Tmp = new Model.G_AchatVente(chConnexion).Lire_ID(AchatSelectionnee.idOperation);
         UnAchat             = new VM_UnAchat();
         UnAchat.IDOperation = Tmp.idOperation;
         UnAchat.IDVoiture   = Tmp.idVoiture;
         UnAchat.IDClient    = Tmp.idClient;
         UnAchat.Prix        = Tmp.prixOperation;
         UnAchat.Date        = Tmp.dateOperation;
         UnAchat.IDPaiement  = Tmp.idPaiement;
         UnAchat.Type        = Tmp.typeOperation;
         nAjout          = BcpAchats.IndexOf(AchatSelectionnee);
         ActiverUneFiche = true;
     }
 }