Applet Problems

import java.applet.*;
import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class PrimarySC extends Applet implements Runnable, KeyListener {
	private static final long serialVersionUID = 1L;
	public void init() {
		setSize(400,400);
		setBackground(Color.white);
	}
	public void start() {
		Thread th = new Thread(this);
		 th.start();
	}
	public void stop() {
	}
	public void run() {
		Thread.currentThread().setPriority(Thread.MIN_PRIORITY);
		while(true) {

			repaint();
			  try {
			    Thread.sleep(20);
			  } catch (InterruptedException ex) {
			  }
		}
	}
	public void paint (Graphics g) {
		g.setColor(Color.gray);
		g.fillRect(10, 400, 30, 100);
	}
	public void keyPressed(KeyEvent e) {

	}
	public void keyReleased(KeyEvent e) {

	}
	public void keyTyped(KeyEvent e) {
		int c = e.getKeyChar();
	}
}