以下是一个applet动画程序，我想在里面加个JButton  高手帮帮忙，应该怎么加呀？ 谢谢了哦
import java.applet.*;
import java.awt.*;
import java.awt.image.*;
import *;
import javax.swing.*;

public class NationDay extends java.applet.Applet implements Runnable {
    MediaTracker tracker = null;
    int frame_x = 0;
    boolean bz_load = false;
    boolean bz_anima = false;
    int current = 0;
    private boolean init = false;
    private AudioClip m_Audio;
    Image backImage = null;
    Image myImage = null;
    Image allImages[] = null;
    Thread animation = null;
   
    public void init() {
        if(init == false){
            tracker = new MediaTracker(this);
            allImages = new Image[7];
            for(int x=0;x<7;x++)
                allImages[x] = getImage(getDocumentBase(),"Image/Mrab0"+x+".gif");
            for(int x=0;x<7;x++)
                tracker.addImage(allImages[x],x);
            backImage = getImage(getDocumentBase(),"Image/50.gif");
        }
    }
                            //开始动画
    public void paint(Graphics g){
        setBackground(Color.WHITE);
        bz_load = true;
        if(bz_load){
            bz_anima = true;
            g.drawImage(backImage,0,0,this);
            g.drawImage(allImages[current],frame_x,0,this);
        }
        else{
            g.drawString("画面载入中，请稍候......",0,20);
        }
    }
   
    public void start(){
        m_Audio = getAudioClip(getDocumentBase(),"Image/spacemusic.au");
        if(m_Audio != null){
            m_Audio.loop();
            if(animation == null){
                animation = new Thread(this);
                animation.start();
            }
        }
    }
   
    public void stop(){
        if(m_Audio != null)
            m_Audio.stop();
        if(animation != null){
            animation.stop();
            animation = null;
        }
    }
   
                      //反复播放动画
    public void run(){
        while(!checkroll())
            sleep(100);
        bz_load = true;
        while(true){
            roll(0,this.getSize().width-42);
        }
    }
   
    boolean checkroll(){
        boolean finished = true;
        for(int i=0;i<7;i++){
            if((tracker.statusID(i,true)&) == 0)
                finished = false;
        }
        return finished;
    }
   
    void roll(int begin,int end){
        if(begin<end){
            for(int x=begin;x<=end;x+=21){
                frame_x = x;
                repaint();
                current--;
                if(current == -1)
                    current = 3;
                sleep(150);
            }
        }
        else{
            for(int  x=begin;x>=end;x-=21){
                frame_x = x;
                repaint();
                current++;
                if(current == 7)
                    current = 0;
                sleep(150);
            }
        }
    }
   
    public void sleep(int a){
        try{
            Thread.sleep(a);
        }
        catch(InterruptedException e){
        }
    }
   
    public void update(Graphics g){
        g.clipRect(0,0,1000,500);
        paint(g);
    }
}