public ActionResult ValidateKey(ValidateKeyModel viewModel)
        {
            if (!ModelState.IsValid) return View(viewModel);

            //custom validation
            if (viewModel.NewPassword != viewModel.Confirm)
            {
                ModelState.AddModelError("PASSAWORD_AND_CONFIRM_DONT_MACHT", "");
            }
            if (viewModel.Key == "123")
            {
                ModelState.AddModelError("INVALID_KEY", "");
            }

            //retorn of view
            if (ModelState.IsValid)
            {
                return View("ValidateKeySuccess");
            }
            else
            {
                return View(viewModel);
            }
        }
        public ActionResult ValidateKey()
        {
            ValidateKeyModel viewModel = new ValidateKeyModel();
            viewModel.Key = Request["Key"];

            return View(viewModel);
        }