public ActionResult Index(UsuarioPedidoViewModel loginViewModel)
        {
            if (!ModelState.IsValid)
            {
                ModelState.AddModelError("Usuario", "Os dados devem ser preenchidos");
                return View();

            }

            var usuario = new UsuarioDto()
            {
                Usuario = loginViewModel.Usuario,
                Senha   = loginViewModel.Senha
            };

            bool IsValidUser = usuarioLogic.verificaUsuario(usuario);
            if ( !IsValidUser )
            {
                ModelState.Clear();
                ModelState.AddModelError("Usuario", "Usuário inválido");
                ModelState.AddModelError("Senha", "Senha inválida");
                return View();
            }

            criaCookie(loginViewModel);
            return Redirect("/Retrieve");
        }
        private void criaCookie(UsuarioPedidoViewModel model)
        {
            var cookie = FormsAuthentication.GetAuthCookie(model.Usuario, true);
            var ticket = FormsAuthentication.Decrypt(cookie.Value);
            var newTicket = new FormsAuthenticationTicket(ticket.Version, ticket.Name, ticket.IssueDate,
            ticket.Expiration, ticket.IsPersistent, model.Usuario, ticket.CookiePath);
            var encTicket = FormsAuthentication.Encrypt(newTicket);
            cookie.Value = encTicket;

            System.Web.HttpContext.Current.Response.Cookies.Add(cookie);
        }