[HttpPost]
public ActionResult Login(LoginViewModel login)
{
    if (!ModelState.IsValid)
    {
        ViewBag.Error = "Form is not valid; please review and try again.";
        return View("Login");
    }

    if (login.Username == "bpradmin" && login.Password == "admin123")
        FormsAuthentication.RedirectFromLoginPage(login.Username, true);

    ViewBag.Error = "Credentials invalid. Please try again.";
    return View("Login");
}