Java sample(RadioButton & TextField)

//Example03
import java.awt.*;
import java.awt.event.*;
public class Example03 extends Frame implements ItemListener{
  TextField tf01=new TextField("",60);
  TextField tf02=new TextField("",20);
  CheckboxGroup cbg=new CheckboxGroup();
  int pc=-1;
  //Main
  public static void main(String ar[]){
    Frame f=new Example03();
    f.setTitle("RadioButton & TextField");
    f.setSize(640,400);
    f.setVisible(true);
  }
  //RadioButton
  Example03(){
    setLayout(new FlowLayout());
    Checkbox rb1 = new Checkbox("abc", cbg, true);
    Checkbox rb2 = new Checkbox("xyz", cbg, false);
        rb1.addItemListener(this);
        rb2.addItemListener(this);
    add(rb1);
    add(rb2);
    add(tf01);
    add(tf02);
    addWindowListener(new WinAdapter());
  }
  //Close
  class WinAdapter extends WindowAdapter{
    public void windowClosing(WindowEvent we){System.exit(0);}
  }
  //Paint
  public void paint(Graphics g){
    String s0="AAAAAA";
    String s1="BBBBBBBBB";
    if(pc>-1){
      tf01.setText("");
      tf02.setText("");
    }
    if(pc==0){
      tf01.setText(s0);
      tf02.setText(s1);
    }
    if(pc==1){
      tf01.setText(s1);
      tf02.setText(s0);
    }
  }
    public void itemStateChanged(ItemEvent ie){
    if(cbg.getSelectedCheckbox().getLabel() =="abc"){
      pc=0;
      repaint();
    }
    if(cbg.getSelectedCheckbox().getLabel() =="xyz"){
      pc=1;
      repaint();
    }
    }
}