import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class DialogExample {
    private static JDialog dialog;

    public DialogExample() {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        dialog = new JDialog(frame, "New Dialog Box", true);
        dialog.setLayout(new FlowLayout());
        dialog.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);

        JButton button = new JButton("OK");
        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                DialogExample.dialog.setVisible(false);
            }
        });

        dialog.add(new JLabel("Click OK to Agree"));
        dialog.add(button);
        dialog.setSize(250, 250);
        dialog.setVisible(true);
    }

    public static void main(String[] args) {
        new DialogExample();
    }
}