public ActionResult Edit(PromocionViewModels pr)
        {
            if (ModelState.IsValid)
            {
                App_Start.AutoMapperWebConfiguration.Configure();
                dtoPromocion DTO = Mapper.Map <PromocionViewModels, dtoPromocion>(pr);

                var bll = new dtoPromocion();
                bll.Actualizar(DTO);

                return(RedirectToAction("Index"));
            }
            else
            {
                return(View(pr));
            }
        }