private void btnView_Click(object sender, RoutedEventArgs e)
        {
            if (selectedClient != null)
            {
                btnView.IsEnabled = false;
                CaisseServiceClient Service = new CaisseServiceClient(Utility.ProtocoleFacturation(), Utility.EndPoint("Caisse"));
                Service.RetourneListeFactureNonSoldeCompleted += (s, results) =>
                {
                    if (results.Cancelled || results.Error != null)
                    {
                        MessageBox.Show("error d'invocation du service");
                        btnView.IsEnabled = true;
                        return;
                    }

                    if (results.Result == null)
                    {
                        MessageBox.Show("no data match for those criteria");
                        btnView.IsEnabled = true;
                        return;
                    }
                    else
                    {
                        if (results.Result.Count > 0)
                        {
                            List <CsLclient> _lstFact = results.Result;
                            //if (_rang == 2)
                            //{
                            //    if (this.comboBox1.SelectedItem.ToString() == "=")
                            //        _lstFact = _lstFact.Where(p => p.MONTANT == Convert.ToDecimal(this.txtreference.Text)).ToList();
                            //    else if (this.comboBox1.SelectedItem.ToString() == ">=")
                            //        _lstFact = _lstFact.Where(p => p.MONTANT >= Convert.ToDecimal(this.txtreference.Text)).ToList();
                            //    else if (this.comboBox1.SelectedItem.ToString() == "<=")
                            //        _lstFact = _lstFact.Where(p => p.MONTANT <= Convert.ToDecimal(this.txtreference.Text)).ToList();
                            //}

                            _lstFact.ForEach(p => p.REFEMNDOC = p.REFEM + "-" + p.NDOC);
                            _lstFact.ForEach(p => p.NOM       = selectedClient.NOMABON);
                            List <CsClient>       clients = new List <CsClient>();
                            UcConsulClientAccount consult = new UcConsulClientAccount(_lstFact);
                            consult.Closed += new EventHandler(UcConsulClientAccountClosed);
                            consult.Show();
                        }
                        else
                        {
                            Message.ShowInformation("Ce Client n'a pas de facture", "information");
                        }
                        btnView.IsEnabled = true;
                    }
                };
                Service.RetourneListeFactureNonSoldeAsync(selectedClient);
            }
            else
            {
                MessageBox.Show("No Item selected in the Grid");
            }

            //passage++;
        }