public IActionResult Account()
        {
            ViewData["Message"] = "Your application description page.";

            DataObj dataObj = new DataObj(appSetting);
            int     userId  = Int32.Parse(HttpContext.Session.GetString("UserID"));
            string  email   = dataObj.getUserEmail(userId);

            return(View("Account", email));
        }
        public ActionResult Account(string email)
        {
            Regex rx = new Regex(@"^[\w-\.]+@([\w-]+\.)+[\w-]{2,4}$");

            if (rx.IsMatch(email))
            {
                DataObj dataObj = new DataObj(appSetting);
                int     userId  = Int32.Parse(HttpContext.Session.GetString("UserID"));
                dataObj.updateUserEmail(userId, email);
                email = dataObj.getUserEmail(userId);
                ViewData["Success"] = "Email updated successfully.";
                return(View("Account", email));
            }
            else
            {
                ViewData["Error"] = "You did not enter a valid email address.";
            }
            return(View("Account", email));
        }