import java.applet.*; 
import java.awt.*; 
import java.awt.event.*; 

public class MyApplet extends Applet implements MouseListener 
{ 
  Checkbox MyCheckbox1, MyCheckbox2, MyCheckbox3; 
  CheckboxGroup MyCheckboxGroup; 
  Button MyButton; 

  public void init() 
  { 
    setLayout(new GridLayout(4, 1)); 
    MyCheckboxGroup = new CheckboxGroup(); 
    MyCheckbox1 = new Checkbox("MyCheckbox 1", MyCheckboxGroup, true); 
    MyCheckbox2 = new Checkbox("MyCheckbox 2", MyCheckboxGroup, false); 
    MyCheckbox3 = new Checkbox("MyCheckbox 3", MyCheckboxGroup, false); 
    MyButton = new Button("MyButton"); 
    MyButton.addMouseListener(this); 
    add(MyCheckbox1); 
    add(MyCheckbox2); 
    add(MyCheckbox3); 
    add(MyButton); 
  } 

  public void mouseReleased(MouseEvent ev) 
  { 
    Checkbox Active = MyCheckboxGroup.getSelectedCheckbox(); 
    MyButton.setLabel(Active.getLabel()); 
  } 

  public void mousePressed(MouseEvent ev) { } 
  public void mouseEntered(MouseEvent ev) { } 
  public void mouseExited(MouseEvent ev) { } 
  public void mouseClicked(MouseEvent ev) { } 
}