protected void btnSave_Click(object sender, EventArgs e) { if (HttpContext.Current.Session["Employee"] == null) { Response.Redirect("~/login.aspx", false); Context.ApplicationInstance.CompleteRequest(); } List <Order> updatedOrders = (List <Order>)HttpContext.Current.Session["UpdatedOrders"]; if (updatedOrders != null) { sqC = new sqlController(); foreach (Order order in updatedOrders) { sqC.updateOrderBillID(order); } sqC = null; } server = (Server)HttpContext.Current.Session["Employee"]; table = server.getTable(Int32.Parse(HttpContext.Current.Session["TableNum"].ToString())); List <Bill> bills = table.GetBills(); if (updatedOrders != null) { foreach (Bill bill in bills) { if (bill.ID == 0 && bill.Orders.Count > 0) { bill.SaveBill(); } bill.CalculateTotal(); bill.Update(); } } RemoveEmptyBills(bills); Session["Employee"] = server; Response.Redirect("~/Sales_App/tblDetails.aspx?Table=" + Int32.Parse(table.TableNumber.ToString()), false); Context.ApplicationInstance.CompleteRequest(); }