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


class Main2{
  public static void main(String[] args){

    try {
      UIManager.setLookAndFeel(
      UIManager.getCrossPlatformLookAndFeelClassName());
    } catch (Exception e) { System.exit(1); }


    JFrame vindu = new JFrame("Vaart Vindu");
    vindu.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel panel = new JPanel();
    vindu.add(panel);

    panel.setLayout(new GridLayout(4,1));

    JButton knapp1 = new JButton();
    panel.add(knapp1);
    JButton knapp2 = new JButton();
    panel.add(knapp2);
    JButton knapp3 = new JButton();
    panel.add(knapp3);
    JButton knapp4 = new JButton();
    panel.add(knapp4);

    knapp1.setBackground(Color.BLUE);
    knapp2.setBackground(Color.RED);
    knapp3.setBackground(Color.YELLOW);
    knapp4.setBackground(Color.GREEN);

    class Skriver implements ActionListener{
      @Override
      public void actionPerformed(ActionEvent e){
        System.out.println("Blaa!!");
      }
    }
    class Skriver2 implements ActionListener{
      @Override
      public void actionPerformed(ActionEvent e){
        System.out.println("Roed!!");
      }
    }
    class Skriver3 implements ActionListener{
      @Override
      public void actionPerformed(ActionEvent e){
        System.out.println("Gul!!");
      }
    }
    class Skriver4 implements ActionListener{
      @Override
      public void actionPerformed(ActionEvent e){
        System.out.println("Groenn!!");
      }
    }

    knapp1.addActionListener(new Skriver());
    knapp2.addActionListener(new Skriver2());
    knapp3.addActionListener(new Skriver3());
    knapp4.addActionListener(new Skriver4());

    vindu.pack();
    vindu.setVisible(true);

  }
}