private void FillCollector()
        {
            try
            {
                int loaderHandler = LoadingManager.BeginLoading("Please Wait for pass payment ... ");
                ddbCollecter.Items.Clear();
                ReportServiceClient service = new ReportServiceClient(Utility.Protocole(), Utility.EndPoint("Report"));
                service.SELECT_ALL_COLLECTORSAsync();
                service.SELECT_ALL_COLLECTORSCompleted += (er, res) =>
                {
                    try
                    {
                        if (res.Error != null || res.Cancelled)
                        {
                            LoadingManager.EndLoading(loaderHandler);
                            throw new Exception("Cannot display report");
                        }

                        if (res.Result != null)
                        {
                            //Code en cas de succès
                            foreach (var item in res.Result)
                            {
                                listeDesCaissieres_.Add(item);
                            }
                            ddbCollecter.ItemsSource = listeDesCaissieres_;
                            //ddbCollecter.Items.Add("");
                            //foreach (Galatee.Silverlight.ServiceReport.CParametre collecteur in listeDesCaissieres)
                            //    ddbCollecter.Items.Add(collecteur.LIBELLE);
                        }
                    }
                    catch (Exception ex)
                    {
                        MessageBox.Show(ex.Message);
                    }
                    finally
                    {
                        LoadingManager.EndLoading(loaderHandler);
                    }
                };
            }
            catch (Exception)
            { }
        }