public IActionResult DoLogIn(LogInViewModel logInViewModel)
        {
            // Get the Id of the User
            var userId = _userBusinessLogic.LogIn(logInViewModel.Name, logInViewModel.Pass);

            // Check if the login failed
            if (userId == null)
            {
                return(View("Index", new LogInViewModel()
                {
                    ErrorMessage = "Incorrect username or password"
                }));
            }

            // Create new Session
            HttpContext.Session.SetInt32("UserId", (int)userId);

            // Pass the success-message through the TempData, because the model cannot be passed
            TempData["SuccessMessage"] = "Successfully logged in";

            return(RedirectToAction("Index", "Home"));
        }