public ActionResult Login(LoginViewModel login, string returnUrl)
        {
            if (!ModelState.IsValid)
            {
                return(View(login));
            }

            var achou = (UsuarioViewModel.ValidaUsuario(login.Usuario, login.Senha));

            if (achou)
            {
                FormsAuthentication.SetAuthCookie(login.Usuario, login.LembrarMe);

                if (Url.IsLocalUrl(returnUrl))
                {
                    returnUrl = "/Cadastrar/Livro";
                    return(Redirect(returnUrl));
                }
                else
                {
                    return(RedirectToAction("Index", "Home"));
                }
            }
            else
            {
                ModelState.AddModelError("", "Login inválido!");
            }

            return(View(login));
        }