private void savePrintButton_Click(object sender, EventArgs e)
        {
            orderUser.FirstName    = firstNameTextBox.Text;
            orderUser.LastName     = lastNameTextBox.Text;
            orderUser.BillType     = billTypeTextBox.Text;
            orderUser.PurchaseDate = billDate.Value.ToString("dd-MM-yyyy");
            int OrderUserId = 0;

            bool isAddOrderUser = _purchaseManager.AddOrderUser(orderUser);

            DataTable dataTable1 = _purchaseManager.OUserId();

            foreach (DataRow dr in dataTable1.Rows)
            {
                OrderUserId = Convert.ToInt32(dr["Id"].ToString());
            }

            foreach (DataRow dr in dt.Rows)
            {
                orderItem.Product  = dr["Product"].ToString();
                orderItem.Price    = Convert.ToDouble(dr["Price"].ToString());
                orderItem.Quantity = Convert.ToInt32(dr["Quantity"].ToString());
                orderItem.Total    = Convert.ToInt32(dr["Total"].ToString());

                bool isAddOrderItem = _purchaseManager.AddOrderItem(orderItem, OrderUserId);

                _purchaseManager.UpdateStockQty(orderItem);
            }

            dt.Clear();
            showDataGridView.DataSource = dt;
            MessageBox.Show("Iserted Successfully..");
        }