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

public class blokje extends Actor
{

    public void act() 
    {
       setLocation(getX(), getY()+1);
       removeFromWorld();
       getLocation();
    }    
 public void removeFromWorld()  
{  
    if (Greenfoot.isKeyDown("q"))  
    {  
        getWorld();
        setImage(new GreenfootImage("grijs.png"));
        getWorld().addObject(new blokje(), Greenfoot.getRandomNumber(4), 0 );
    }
    if (Greenfoot.isKeyDown("w"))  
    {  
        getWorld();
        setImage(new GreenfootImage("grijs.png"));
        getWorld().addObject(new blokje(), Greenfoot.getRandomNumber(4), 0 );
    }
    if (Greenfoot.isKeyDown("e"))  
    {  
        getWorld();
        setImage(new GreenfootImage("grijs.png"));
        getWorld().addObject(new blokje(), Greenfoot.getRandomNumber(4), 0 );
    }
    if (Greenfoot.isKeyDown("r"))  
    {  
        getWorld();
        setImage(new GreenfootImage("grijs.png"));
        getWorld().addObject(new blokje(), Greenfoot.getRandomNumber(4), 0 );
    }
}        
     //this part is my problem:
   public void getLocation()
        {
        if (Greenfoot.)
        {
        getWorld();
        getLocation(getX(), getY()==3);
        removeObject(this);
    }
}
    
    }