public IActionResult Index()
        {
            var            customerItems = context.Customer.GetAll().ToList();
            var            productItems  = context.Product.GetAll().ToList();
            var            vatItems      = context.VatAndTax.GetAll().ToList();
            SalesInvoiceVM salesInvoice  = new SalesInvoiceVM()
            {
                CustomerItem = POSHelper.Customer(customerItems),
                ProductItem  = POSHelper.Product(productItems),
                VatItem      = POSHelper.VatAndTax(vatItems),
            };

            return(View(salesInvoice));
        }
        public IActionResult Index()
        {
            var supplierList = context.Supplier.GetAll().ToList();
            var productList  = context.Product.GetAll().ToList();
            var vatAndTax    = context.VatAndTax.GetAll().ToList();

            PurchaseProductVM purchaseProduct = new PurchaseProductVM()
            {
                SupplierItem = POSHelper.Supplier(supplierList),
                ProductItem  = POSHelper.Product(productList),
                VatItem      = POSHelper.VatAndTax(vatAndTax),
            };

            return(View(purchaseProduct));
        }