Java program to implement a moving banner

import java.io.*;
import java.awt.*;
import java.applet.*;
/* <applet code=banner height=200 width=200></applet> */
public class banner extends Applet implements Runnable
{
String msg="A moving banner";
boolean st;
Thread t=null;
int state;
public void init()
{
}
public void start()
{
t=new Thread(this);
st=false;
t.start();
}
public void run()
{
char ch;
for(;;)
{
try
{
repaint();
Thread.sleep(250);
ch=msg.charAt(0);
msg=msg.substring(1,msg.length());
msg=msg+ch;
if(st)
break;
}
catch(Exception e)
{
}
}
}
public void stop()
{
st=true;
t=null;
}
public void paint(Graphics g)
{
 g.drawString(msg,50,50);
}
}