public IActionResult CustomerOrders(int?CustomerID = null, int?SortBy = null)
        {
            var customers = _customerBL.GetCustomers();

            ViewBag.Customers = customers
                                .Select(i => new SelectListItem
            {
                Value = i.CustomerId.ToString(),
                Text  = i.Name
            }).ToList();
            ViewBag.SortOptions = GetSortOptions();

            CustomerOrdersVM customerOrdersVM = _orderBL.GetCustomerOrdersVM(CustomerID, SortBy);

            return(View(customerOrdersVM));
        }