// GET: Promotion
        public ActionResult Index()
        {
            var promotion = new PromotionViewModel();
            using (var unitOfWork = new UnitOfWork())
            {

               var result = unitOfWork.GetPromotionDetailByUsername(User.Identity.Name);

                if (result != null)
                {
                    promotion = new PromotionViewModel()
                    {
                        PromotionId = result.PromotionId,
                        Description = result.Description,
                        EndDate = result.EndDate,
                        Expertise = result.Expertise,
                        Price = result.Price,
                        StartDate = result.StartDate

                    };
                    var resultTags = unitOfWork.GetPromotionTagsByPromotionId(promotion.PromotionId).Select(x => new TagViewModel()
                    {
                        Tag = x.Tag,
                        TagId = x.TagId

                    }
                    );

                    promotion.Tags = resultTags.ToList();
                }
                else
                {
                    return RedirectToAction("Create");
                }
            }
                return View(promotion);
        }