public static void deliver(int where, String what) {
        switch (where) {
            case EVENT_AREA: ((MainWindow) GUI_Destination).setEventText(what); break;
            case SYNTAX_AREA: ((MainWindow) GUI_Destination).setSyntaxText(what); break;
            case ERROR: 
                if(GUI_Origin instanceof NewOperations) {
                    ((NewOperations) GUI_Origin).showError(what);
                } else {
                    System.err.println("Origen Desconocido");
                }
                break;
            default: System.err.println("Destino desconocido"); break;
        }
    }