谢谢各位高手，把程序粘一下，帮我看看吧，急~！

import java.awt.*;
import java.text.DateFormat;
import java.applet.*;
public class Clock extends Applet implements Runnable
{
private Thread clockThread;

public void init()
{
setBackground(Color.white);
clockThread=null;
}

public void start()
{
if(clockThread==null)
{
clockThread=new Thread(this,"Clock");
clockThread.start();
}

}

public void run()
{
while(clockThread!=null)
{
repaint();
try
{
Thread.sleep(1000);
}

catch(InterruptedException e)
{
}

}

}

public void paint(Graphics g)
{
Date date=new Date();
DateFormat dateFormatter=DateFormat.getTimeInstance();

g.setFont(new Font("Serif",Font.BOLD,34));
g.drawString(dateFormatter.format(date),5,30);
}

public void stop()
{
clockThread=null;
}
}

//谢上咋修改啊！谢谢