Solution

HTML Interface to Applet

<APPLET CODEBASE="/applets/magelang/AWT-Training/classes/" CODE="RegistrationForm.class" WIDTH=495 HEIGHT=310 ALIGN=CENTER></APPLET>

Java Code

import java.awt.*;

/**
 * Simple fill-out form (w/verification) using custom
 * components and a custom layout manager for placement of
 * the overall applet.
 */
public class RegistrationForm extends java.applet.Applet {
    protected Button submit;
    protected RadioButtons course;
    protected ContactInfoForm contact;
    protected JobTitleList job;
    protected CommentBox comment;
    
    /**
     * Called once to initialize the Applet.
     * Create Components, lay them out, and perform any
     * initializations here.
     */
    public void init() {
        setFont(new Font("Dialog", Font.BOLD, 12));
        setBackground(Color.white);
        
        Label title = new Label("Course Registration");
        title.setFont(new Font("Dialog", Font.BOLD, 18));

        Panel mainPanel = new Panel();
        mainPanel.setLayout(new FlowLayout(FlowLayout.CENTER, 20, 0));
        course = new RadioButtons();
        contact = new ContactInfoForm();
        job = new JobTitleList();
        comment = new CommentBox();
        mainPanel.add(course);
        mainPanel.add(contact);
        mainPanel.add(job);
        mainPanel.add(comment);

        submit = new Button("Submit");

        setLayout(new RatioLayout());
        add("c,0", title);  // center title at top
        add("0,.1;1,.8", mainPanel); // put below title, span x, 80% in y
        add("c,.90", submit); // center button near bottom
    }

    /**
     * Respond to a "Submit" button press
     */
    public boolean action(Event event, Object arg) {
        if (event.target == submit) {
            // if any element is non-empty, then give error
            if ( course.isEmpty() || contact.isEmpty() || job.isEmpty() ) {
                System.err.println("You must fill in all required " +
                                   "fields before you can submit " +
                                   "the form");
                return true;
            }
            // dump all contents
            System.out.println(course.getContents());
            System.out.println(contact.getContents());
            System.out.println(job.getContents());
            System.out.println(comment.getContents());
            return true;
        }
        return false;
    }
}