public GuiArancel(Arancel a) {
        super();
        initComponents();
        this.a = a;
        this.setVisible(true);
        this.setLocationRelativeTo(null);
        if (a.getAra() != 0) {
            this.setTitle("MODIFICA ARANCEL");
        } else {
            this.setTitle("REGISTRAR ARANCEL");
        }
        this.leerDatos();
    }