HELP!

import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
/**
 * Write a description of class Worldy here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */
public class Worldy extends Scrollworld implements ActionListener
{
    public static final Font MED_FONT = new Font("SansSerif", Font.BOLD, 50);
    private Button startBtn;
    private Button onOffBtn;
    private boolean enabled = true;
    private Border redBorder = new LineBorder(Color.RED, 3);
    private Border blueBorder = new LineBorder(Color.BLUE, 3);
    private int L=0;
    private int T=0;
    private int X;
    private int Y;
    public tankBase tank;
    public enemyTankHead tH;
    /**
     * Constructor for objects of class Worldy.
     * 
     */
    public Worldy()
    {
        super(2500, 2500, 600, 600, 1250, 1250, 1);
        Level(1);
    }
    public void Level(int l)
    {
        if(l==1){
            menuSetup();
        }
        if(l==2){
            removeObject(startBtn);
            newBackground("rivets.jpg");
            addObject(new tankBase(),300,300);
            addObject(new tankHead(),300,300);
        }
        L=l;
    }
    public void act()
    {
        if(L==2){
            if(T==0){
                X=Greenfoot.getRandomNumber(2416)+42;
                Y=Greenfoot.getRandomNumber(2416)+42;
                addObject(new enemyTankBase(),X,Y);
                addObject(new enemyTankHead(),X,Y);
                T=2000;
            }else{
                T--;
            }
        }
    }
    public void done(int level)
    {
        Level(level+1);
    }
    public void menuSetup()
    {
        newBackground("Wall.jpg");
        startBtn = new Button(new GreenfootImage("roundedbtn-up.png"),
            new GreenfootImage("roundedbtn-down.png"),
            new GreenfootImage("roundedbtn-hover.png"));
        startBtn.setForeground(Color.BLACK);
        startBtn.setText("Start");
        startBtn.setSize(new Dimension(200, 65));
        startBtn.setFont(MED_FONT);
        startBtn.setID(1008);
        startBtn.addActionListener(this);
        addObject(startBtn, 300, 300);
    }
    public void actionPerformed(GUIComponent c) {
        if (c != onOffBtn) {
            done(1);
        } else {
            enabled = !enabled;
            
            startBtn.setEnabled(enabled);
            
            if (enabled) {
                c.setText("Disable\nComponents");
            } else {
                c.setText("Enable\nComponents");
            }
        }
    }
    public int StareX()
    {
        return tank.getX();
    }
    public int StareY()
    {
        return tank.getY();
    }
}

import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)

/**
 * Write a description of class tankHead here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */
public class enemyTankHead extends Mover
{
    public int shotTimer=0;
    private GreenfootSound rotate;
    private GreenfootSound shoot;
    public enemyTankHead()
    {
        rotate = new GreenfootSound("Motor.wav");
        rotate.setVolume(70);
        shoot = new GreenfootSound("Bang.wav");
        shoot.setVolume(80);
    }
    public void act() 
    {
        Controll();
    }
    public void Controll()
    {
        Worldy worldy = (Worldy) getWorld();
        turnTowards(worldy.StareX(),worldy.StareY());
        if(Greenfoot.isKeyDown("left")){
            rotate.play();
        }else if(Greenfoot.isKeyDown("right")){
            rotate.play();
        }else{
            rotate.pause();
        }
        if (shotTimer > 0) {
            shotTimer--;
        }
        else if(Greenfoot.isKeyDown("space"))
        {
            Fire();
            shotTimer = 30;
            shoot.play();
        }
        Actor base;
        base = getOneIntersectingObject (enemyTankBase.class);
        setLocation(base.getX(),base.getY());
    }
    public void Fire()
    {
        Bullet b = new Bullet();  
        getWorld().addObject(b,getX(),getY());
        b.getImage().scale(5,5);
        b.setRotation(getRotation());  
        b.move(50);
    }
}