private void BtnAddInvoiceDetail_Click(object sender, EventArgs e)
        {
            if (butonApasat != 1)
            {
                invoiceform.Show();

                List <InvoiceDetailModel> invoicedetail      = new List <InvoiceDetailModel>();
                InvoiceDetailModel        invoicedetailModel = new InvoiceDetailModel();
                invoicedetail = invoiceDetailModels;

                invoicedetailModel.InvoiceDetailId = 0;
                invoicedetailModel.InvoiceId       = invoiceform.InvoiceId;
                invoicedetailModel.Item            = new ItemModel
                {
                    ItemName = comboBoxItem.SelectedItem.ToString(),
                    ItemId   = Convert.ToInt32(comboBoxItem.SelectedIndex.ToString())
                };
                invoicedetailModel.Qtty         = Convert.ToDecimal(txtBoxQtty.Text);
                invoicedetailModel.Price        = Convert.ToDecimal(txtBoxPrice.Text);
                invoicedetailModel.Amount       = Convert.ToDecimal(txtBoxAmount.Text);
                invoicedetailModel.Observations = txtObservations.Text.ToString();
                invoicedetailModel.status       = 1;
                invoicedetail.Add(invoicedetailModel);
                invoiceform.refreshGrid(invoicedetail);

                butonApasat = 0;
                this.Close();
            }
            else
            {
                invoiceform.Show();

                List <InvoiceDetailModel> invoicedetail      = new List <InvoiceDetailModel>();
                InvoiceDetailModel        invoicedetailModel = new InvoiceDetailModel();
                invoicedetail = invoiceDetailModels;
                for (int i = 0; i < invoicedetail.Count; i++)
                {
                    if (invoicedetail[i].status == 2)
                    {
                        invoicedetailModel.InvoiceDetailId = 0;
                        invoicedetailModel.InvoiceId       = invoiceform.InvoiceId;
                        invoicedetailModel.Item            = new ItemModel
                        {
                            ItemName = comboBoxItem.SelectedItem.ToString(),
                            ItemId   = Convert.ToInt32(comboBoxItem.SelectedIndex.ToString())
                        };
                        invoicedetailModel.Qtty         = Convert.ToDecimal(txtBoxQtty.Text);
                        invoicedetailModel.Price        = Convert.ToDecimal(txtBoxPrice.Text);
                        invoicedetailModel.Amount       = Convert.ToDecimal(txtBoxAmount.Text);
                        invoicedetailModel.Observations = txtObservations.Text.ToString();
                        invoicedetailModel.status       = 2;

                        invoicedetail[i] = invoicedetailModel;
                        invoiceform.refreshGrid(invoicedetail);
                        butonApasat = 0;
                        this.Close();
                    }
                }
            }
        }