public ActionResult Edit(int?id = null)
        {
            ViewBag.IsEdit = true;

            if (id == null)
            {
                return(RedirectToAction("Index"));
            }

            SalesmanBusiness business = new SalesmanBusiness();

            SalesmanViewModel model = business.GetDetail(id.Value);

            if (model == null)
            {
                TempData["AlertMessage"] = new AlertMessage(StaticMessage.ERR_DATA_NOT_FOUND);

                return(RedirectToAction("Index"));
            }

            return(View(model));
        }