@FXML
    private void createAccountButtonClicked() { // Create Admin Account on first-time app use.
        login_icon.setVisible(false); // Blue "Person" Icon Badge.
        if(!new_username_text_field.getText().isEmpty() && !password_text_field.getText().isEmpty() && !new_username_text_field.getText().contains(" ") && new_username_text_field.getText().length() >= 6  && !password_text_field.getText().contains(" ") && password_text_field.getText().length() >= 6) {
            Airport.writeToDb("login.db", "INSERT INTO LoginAccounts (Username, Password, `Admin Privileges`) VALUES('" + new_username_text_field.getText() + "', '" + password_text_field.getText() + "', 'YES')"); // YES is to mean it is an Admin.
            incorrect_login_icon.setVisible(false); // If admin fails and then successfully creates the initial account.
            button_createAccount.setStyle("-fx-background-color: #8BC34A; -fx-text-fill: #f7f7f7; -fx-background-radius: 0;");
            new_username_text_field.setStyle(username_combo_box.getStyle() + " -fx-prompt-text-fill: #000000;");
            password_text_field.setStyle(password_text_field.getStyle() + " -fx-prompt-text-fill: #000000;");
            correct_login_icon.setVisible(true);
            FadeTransition admin_paneFadeIn = new FadeTransition(Duration.millis(1000), post_login_pane); // Fades In Admin Panel
            admin_paneFadeIn.setFromValue(0);
            admin_paneFadeIn.setToValue(1);
            admin_paneFadeIn.play();
            post_login_pane.setDisable(false);
            split_pane.setDisable(false);
            split_pane.setVisible(true);
            split_pane.setDividerPositions(0.2);
            admin_notification_pane.setDisable(false);
            admin_notification_pane.setVisible(true);
            notification = new JFXSnackbar();
            notification.registerSnackbarContainer(main_pane);
            notification.getStyleClass().add("GREEN");
            notification.show("Welcome!", 3000);
        }
        else {
            incorrect_login_icon.setVisible(true);
            button_createAccount.setStyle("-fx-background-color: #E81123; -fx-text-fill: #f7f7f7; -fx-background-radius: 0;");
            new_username_text_field.setStyle(username_combo_box.getStyle() + " -fx-prompt-text-fill: #E81123;");
            password_text_field.setStyle(password_text_field.getStyle() + " -fx-prompt-text-fill: #E81123;");
            notification = new JFXSnackbar();
            notification.registerSnackbarContainer(main_pane);
            notification.show("No Spaces, Minimum 6 characters!", 3000);
        }
    }
    @FXML
    private void enter_key_to_loginPressed(KeyEvent event) { // Press enter to login. (only if username or password field is focused).
        if(!button_createAccount.isDisabled() && post_login_pane.isDisabled() && event.getCode().equals(KeyCode.ENTER)) // Making sure it only catches Enter key and BEFORE the post login pane is showed.
            createAccountButtonClicked(); // Calls all the behaviours that create account button has.
        else if(button_createAccount.isDisabled() && post_login_pane.isDisabled() && event.getCode().equals(KeyCode.ENTER))
            login_buttonClicked(); // Calls all the behaviours that login button has (login check).
    }
    @FXML
    private void login_buttonClicked() { // Login Check.
        ObservableList<ObservableList> dbPassword = Airport.readFromDb("login.db", "SELECT Password FROM LoginAccounts WHERE Username='" + username_combo_box.getValue() + "';");
        ObservableList<ObservableList> isAdmin = Airport.readFromDb("login.db", "SELECT `Admin Privileges` FROM LoginAccounts WHERE Username='" + username_combo_box.getValue() + "';");
        login_icon.setVisible(false);
        if(dbPassword.get(0).contains(password_text_field.getText())) {
            login_button.setPrefWidth(75);
            login_button.setText("Logged in!");
            login_button.setStyle("-fx-background-color: #8BC34A; -fx-text-fill: #f7f7f7; -fx-background-radius: 0;");
            incorrect_login_icon.setVisible(false);
            correct_login_icon.setVisible(true);
            FadeTransition admin_paneFadeIn = new FadeTransition(Duration.millis(1000), post_login_pane);
            admin_paneFadeIn.setFromValue(0);
            admin_paneFadeIn.setToValue(1);
            admin_paneFadeIn.play();
            post_login_pane.setDisable(false);
            split_pane.setDisable(false);
            split_pane.setVisible(true);
            split_pane.setDividerPositions(0.2);
            if(isAdmin.get(0).contains("YES")) { // User is Admin.
                admin_notification_pane.setDisable(false);
                admin_notification_pane.setVisible(true);
                notification = new JFXSnackbar();
                notification.registerSnackbarContainer(main_pane);
                notification.getStyleClass().add("GREEN");
                notification.show("Welcome back, " + Arrays.asList(Airport.readFromDb("login.db", "SELECT Username FROM LoginAccounts").get(0).toString().replaceAll("[\\[\\]\\s+]", "").split(",")).get(0) + "!", 3000);
            }
            else { // User is secretary.
                secretary_notification_pane.setDisable(false);
                secretary_notification_pane.setVisible(true);
                add_plane_button.setDisable(true); // Because of no permissions.
                edit_plane_button.setDisable(true);
                delete_plane_button.setDisable(true);
                add_flight_button.setDisable(true); // -||-
                edit_flight_button.setDisable(true);
                delete_flight_button.setDisable(true);
                add_pilot_button.setDisable(true); // -||-
                edit_pilot_button.setDisable(true);
                delete_pilot_button.setDisable(true);
                secretaries_button.setDisable(true);
                secretaries_button.setVisible(false);
                accounts_button.setDisable(true);
                accounts_button.setVisible(false);
                logout_button.setTranslateY(-44); // To move the button 44 pixels up (where the secretaries' one was).
                left_navigation_pane.setTranslateY(14); // Some cosmetics.
            }
        }
        else {
            password_text_field.setText("");
            password_text_field.setPromptText("Incorrect Password!");
            login_button.setStyle("-fx-background-color: #E81123; -fx-text-fill: #f7f7f7; -fx-background-radius: 0;");
            incorrect_login_icon.setVisible(true);
        }
    }
    @FXML
    private void logout_buttonClicked(ActionEvent event) throws Exception {
        ((Stage)((JFXButton)event.getSource()).getScene().getWindow()).close(); // Closes the current session.
        Airport app = new Airport(); // Creates an Main object (Airport) so we can call its non-static method bellow (start).
        Stage stage = new Stage(); // Creates a new stage (session).
        app.start(stage); // Starts it.
    }