public ActionResult Login(UserViewModel model, string returnUrl)
        {
            if (ModelState.IsValid)
            {
                var username  = model.Username;
                var password  = model.Password;
                var userValid = SqLiteDatabase.Authenticate(username, password);

                if (userValid)
                {
                    FormsAuthentication.SetAuthCookie(username, model.RememberMe);
                    return(RedirectToAction("Index", "Main"));
                }
                else
                {
                    ModelState.AddModelError("", "The user name or password provided is incorrect.");
                }
            }

            return(View(model));
        }