private void btnExitActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_btnExitActionPerformed
        // TODO add your handling code here:
         int selectedOption = JOptionPane.showConfirmDialog(null, 
                                  "Are you sure you want to EXIT the program?", 
                                  "Choose", 
                                  JOptionPane.YES_NO_OPTION); 
if (selectedOption == JOptionPane.YES_OPTION) {
            System.exit(0);
        }
                     
    }//GEN-LAST:event_btnExitActionPerformed