[Java] showConfirmDialog

private void jMenuItem8ActionPerformed(java.awt.event.ActionEvent evt) {
        int odp = JOptionPane.showConfirmDialog(null, "Are you sure");
        switch(odp){
             case JOptionPane.YES_OPTION :{
                System.exit(0);
             }
             break;
             case JOptionPane.NO_OPTION : {
                System.console();
             }
             break;
        }
    }