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

class GuiStart {
    public static void main (String[] arg) {
        try {
            UIManager.setLookAndFeel(
                UIManager.getCrossPlatformLookAndFeelClassName());
        } catch (Exception e) { System.exit(1); }
        
        JFrame vindu = new JFrame("Exit");
        vindu.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel panel = new JPanel();
        vindu.add(panel);

        // Kode her:


        vindu.pack();  
        vindu.setLocationRelativeTo(null);
	    vindu.setVisible(true);
    }
}