private void Button_Login_Click(object sender, RoutedEventArgs e) { User user = new User(); var saver = new Saver(); var Users_List_DB = saver.LOAD_USER(); user = new User(Login: Text_button.Text, Password: Password_button.Password); if (Users_List_DB.CheckForCorrectUserAndPassword(user)) { HasErrorLabel.Foreground = Brushes.Green; HasErrorLabel.Text = "Success enter"; User.currentUser = Users_List_DB.GetCurrentUser(user); AppWidnow appWidnow = new AppWidnow(); this.Hide(); appWidnow.ShowDialog(); this.Show(); } else { HasErrorLabel.Foreground = Brushes.Red; HasErrorLabel.Text = "This user dosen't exist"; } }