if (Request.Cookies["Vouchid"] == null)
        {
            Response.Cookies["Vouchid"].Value = pid.ToString() + ",";
            Response.Cookies["Vouchid"].Expires.AddDays(30);
            if (new ProductService().AddProductsVocuh(pid, IsVouch))
                Response.Write(1);
            Response.End();
        }真是怪了,多少次还是空,为什么呢