public static Admin Login(string pName, string pPwd)
        {
            Admin admin = null;
            bool? isAdmin = false;
            DataContextDataContext dc = new DataContextDataContext();

            ISingleResult<is_adminResult> rs = dc.is_admin(pName, pPwd, ref isAdmin);

            if (isAdmin == true)
            {
                foreach (is_adminResult r in rs)
                {
                    admin = new Admin(r.name, r.pwd, r.mail);
                }
            }
            else
            { }

            return admin;
        }