private void DeleteDebitor()
        {
            if (SelectedDebitor.DebitorId != 0)
            {
                Debitors.Delete(SelectedDebitor.DebitorId);
            }

            FilteredDebitors.Remove(SelectedDebitor);
        }
        private void NewItem()
        {
            CompanyViewModel.Clear();

            if (_SelectedCustomerType == CustomerType.Creditor)
            {
                SelectedCreditor = new Creditor
                {
                    Client = CompanyViewModel.Client
                };
                FilteredCreditors.Add(SelectedCreditor);
                CompanyViewModel.Client = SelectedCreditor.Client;
            }
            else
            {
                SelectedDebitor = new Debitor
                {
                    Client = CompanyViewModel.Client
                };
                FilteredDebitors.Add(SelectedDebitor);
            }
        }