import java.awt.*;
import java.awt.event.*;
import java.lang.*;
import java.lang.Math;

public class Prob2g extends java.applet.Applet 
   {

  CheckboxGroup cbg;
  Checkbox Box0, Box1, Box2, Box3, Box4;
  Button Check;
  Label Response;

  public void init() {

    setBackground(Color.lightGray);
    setLayout(new FlowLayout(FlowLayout.LEFT));
    cbg = new CheckboxGroup();

    Box0 = new Checkbox("28.1 degrees", cbg, true);
    add(Box0);
    Box1 = new Checkbox("31.6 degrees", cbg, false);
    add(Box1);
    Box2 = new Checkbox("50.0 degrees", cbg, false);
    add(Box2);
    Box3 = new Checkbox("61.9 degrees", cbg, false);
    add(Box3);
    Box4 = new Checkbox("all the light is totally reflected internally", cbg, false);
    add(Box4);
   // Check button
    Check = new Button("Check Answer");
    add(Check);

    Response = new Label("Choose the answer you think is correct", Label.CENTER);
    add(Response);

  }

  public boolean action (Event evt, Object arg) {

    if (evt.target instanceof Button) {
      if (cbg.getCurrent().equals(Box0)) {
        Response.setText("Right again!");
      }
      else {
        Response.setText("Sorry...that's incorrect.");
      }
    }
    else return super.action(evt, arg);
    return true;
  }
}