Write a Multithreading program in java to display the number’s between 1 to 100 continuously in a TextField by clicking on button. (use Runnable Interface)

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class MultiThread extends JFrame implements ActionListener
{
    Container cc;
    JButton b1,b2;
    JTextField t1;
    MultiThread()
    {
        setVisible(true);
        setSize(1024,768);
        cc=getContentPane();
        setLayout(null);
        t1=new JTextField(500);
        cc.add(t1);
        t1.setBounds(10,10,1000,30);
        b1=new JButton("start");
        cc.add(b1);
        b1.setBounds(20,50,100,40);
        b1.addActionListener(this);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
    }
    public void actionPerformed(ActionEvent e)
    {
        if(e.getSource()==b1)
        {
            new Mythread();
        }
    }
    class Mythread extends Thread
    {
        Mythread()
        {
        start();
        }
        public void run()
        {
            for(int i=1;i<=100;i++)
            {
                try                {
                    Thread.sleep(1000);
                }
                catch (InterruptedException e) {
                }
                t1.setText(t1.getText()+""+i+"\n");
//System.out.println()            }
        }
    }
    public static void main(String arg[])
    {
        new MultiThread().show();
    }
}