public void sair() {

        if (w == null) {
            int op = JOptionPane.showOptionDialog(null, "You haven't even created a wallet yet ! Do you really wish to leave ?", "Exit", JOptionPane.YES_NO_OPTION, 3, null, null, null);
            if (op == JOptionPane.YES_OPTION) {
                System.exit(0);
            }
        } else {
            int op = JOptionPane.showOptionDialog(null, "Do you wish to save before quiting ?", "Exit", JOptionPane.YES_NO_CANCEL_OPTION, 3, null, null, null);
            if (op == JOptionPane.YES_OPTION) {
                save.getActionListeners()[0].actionPerformed(null);
                if (close) {
                    System.exit(0);
                }
            } else if (op == JOptionPane.NO_OPTION) {
                System.exit(0);
            }
        }
    }