Update Sample applet

Sample applet

@@ -1 +1,44 @@
+package example_applet;
+import java.awt.BorderLayout;
+import java.awt.Color;
+import java.awt.Container;
+import java.awt.HeadlessException;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
 
+import javax.swing.JApplet;
+import javax.swing.JButton;
+
+/*
+ * Created on Oct 6, 2004
+ *
+ * @author Steve Tanimoto
+ */
+@SuppressWarnings("serial")
+public class TrafficLight extends JApplet implements ActionListener {
+	int phase = 0;
+	Container c;
+	/**
+	 * @throws java.awt.HeadlessException
+	 */
+	public TrafficLight() throws HeadlessException {
+		JButton jb = new JButton("Change!");
+		c = this.getContentPane();
+		c.setLayout(new BorderLayout());
+		c.add(jb, BorderLayout.SOUTH);
+		jb.addActionListener(this);
+		c.setBackground(Color.green);
+	}
+	public void actionPerformed(ActionEvent e) {
+		phase = (phase + 1) % 3;
+		if (phase == 0) {
+			c.setBackground(Color.green);
+		}
+		else if (phase == 1) {
+			c.setBackground(Color.yellow);
+		}
+		else if (phase == 2) {
+			c.setBackground(Color.red);
+		}
+	}
+}