private void Login()
        {
            if (LoginModel.Auntenticar(User, Password))
            {
                NavigationPage navigation = new NavigationPage(new HomePage());

                App.Current.MainPage = new MasterDetailPage
                {
                    Master = new HomeMenu(),
                    Detail = navigation
                };
            }
            else
            {
                App.Current.MainPage.DisplayAlert("Mensaje", "Credenciales Invalidas", "OK");
            }
        }