public ActionResult Create(CreateInvoiceItemVm invoiceItem, int?invoice)
        {
            if (ModelState.IsValid)
            {
                InvoiceItem item = new InvoiceItem()
                {
                    Name     = invoiceItem.Name,
                    Price    = invoiceItem.Price,
                    Quantity = invoiceItem.Quantity
                };

                try
                {
                    _repository.CreateInvoiceItem(item, invoice);
                    return(RedirectToAction("Details", "Invoices", new { id = invoice }));
                }
                catch (ArgumentException e)
                {
                    return(new HttpStatusCodeResult(HttpStatusCode.BadRequest));
                }
            }

            return(View(invoiceItem));
        }