public ActionResult ShowTopVoucher()
        {
            var vouchers = db.Vouchers.OrderByDescending(v => v.StartDate).Take(1).FirstOrDefault();

            if (vouchers != null)
            {

                var newVM = new VoucherViewModel()
                {
                    ItemName = vouchers.VoucherName,
                    ItemNameV = vouchers.VoucherNameV,
                    ImageUrl = vouchers.ImageUrl,
                    Price = vouchers.VoucherValue
                };

                return PartialView(newVM);
            }
            return PartialView();
        }
        public ActionResult ShowVoucher()
        {
            var lst = new List<VoucherViewModel>();
            var vouchers = db.Vouchers.ToList();
            foreach (var voucher in vouchers)
            {
                var newVM = new VoucherViewModel()
                {
                    ItemName = voucher.VoucherName,
                    ItemNameV = voucher.VoucherNameV,
                    ImageUrl = voucher.ImageUrl,
                    Price = voucher.VoucherValue,
                    Discount = (int)(voucher.Tour.TourPlans.First().Price / voucher.VoucherValue)
                };
                lst.Add(newVM);
            }

            return PartialView(lst);
        }
        public ActionResult ListVoucher()
        {
            var lst = new List<VoucherViewModel>();
            var vouchers = db.Vouchers.ToList();
            foreach (var voucher in vouchers)
            {
                var newVM = new VoucherViewModel()
                {
                    ItemName = voucher.VoucherName,
                    ItemNameV = voucher.VoucherNameV,
                    ImageUrl = voucher.ImageUrl,
                    Price = voucher.VoucherValue
                };
                lst.Add(newVM);
            }

            return View(lst);
        }