import javax.swing.*;
import java.awt.event.*;
public class Valik1 extends JPanel 
    implements ItemListener, ActionListener{
  JComboBox valik=new JComboBox();
  JTextField tf=new JTextField(15);
  public Valik1(){
     valik.addItem("Juku");
     valik.addItem("Kati");
     valik.addItem("Mati");
     add(valik);
     add(tf);
     valik.addItemListener(this);
     valik.addActionListener(this);
     valik.setEditable(true);
  }
  public void actionPerformed(ActionEvent e){
     if(e.getSource()==valik && valik.getSelectedIndex()==-1){
        valik.addItem(valik.getSelectedItem());
     }
  }
  public void itemStateChanged(ItemEvent e){
     tf.setText(valik.getSelectedItem().toString()+" "+
        valik.getSelectedIndex());
  }
  public static void main(String[] arg){
     JFrame f=new JFrame("Rippmenüü");
     f.add(new Valik1());
     f.setSize(200, 200);
     f.setVisible(true);
  }
}