//file: TrackImage.javaimport java.awt.*;public class TrackImage extends javax.swing.JApplet                        implements Runnable {  final int MAIN_IMAGE = 0;  Image image;  MediaTracker tracker;  boolean loaded = false;  Thread thread = null;  String message = "Loading...";  public void init(  ) {    image = getImage(getClass(  ).getResource(getParameter("image")));    tracker = new MediaTracker(this);    tracker.addImage(image, MAIN_IMAGE);  }  public void start(  ) {    if (!tracker.checkID(MAIN_IMAGE)) {      thread = new Thread(this);      thread.start(  );    }  }  public void stop(  ) {    thread.interrupt(  );    thread = null;  }  public void run(  ) {    repaint(  );    try { tracker.waitForID(MAIN_IMAGE); }    catch(InterruptedException e) {}    if (tracker.isErrorID(MAIN_IMAGE)) message = "Error";    else loaded = true;    repaint(  );  }  public void paint(Graphics g) {    if (loaded) g.drawImage(image, 0, 0, this);    else {      g.drawRect(0, 0, getSize().width - 1, getSize(  ).height - 1);      g.drawString(message, 20, 20);    }  }}