public void startmaingame() {
        if (k != 10 && k >= 1) {
            k--;
        }
        else if (k == 0 && introduction == 0) {            
            k = 10;
            getWorld().removeObjects(getWorld().getObjects(Blowfish.class));
            getWorld().removeObjects(getWorld().getObjects(Jellyfish.class));
            getWorld().removeObjects(getWorld().getObjects(Shark.class));
            getWorld().removeObjects(getWorld().getObjects(Eel.class));
            getWorld().removeObjects(getWorld().getObjects(Swordfish.class));
            getWorld().removeObjects(getWorld().getObjects(Ray.class));
            getWorld().removeObjects(getWorld().getObjects(check.class));
            getWorld().removeObjects(getWorld().getObjects(introduction.class));
            getWorld().removeObjects(getWorld().getObjects(controlsicon.class));
            //Greenfoot.setWorld(new world());
            getWorld().addObject(new rockcounter(), 60, 100);
            getWorld().addObject(new rocksleft(), 70, 20);
            getWorld().addObject(new rocksleftcount(), 155, 20);
            getWorld().addObject(new score(), 670, 20);
            getWorld().addObject(new scorecounter(), 720, 20);
            getWorld().addObject(new health(), 370, 20);
            getWorld().addObject(new display(), 435, 20);
            getWorld().addObject(new Dolphin(), 400, 300);
            world dolphinworld = (world) getWorld();
            maingame++;
            bevorestart.stop();
            dolphinworld.musicplay(); // starts the mainmusic
            getWorld().removeObject(this);
        }
        else if (k == 0 && introduction == 1) {
            getWorld().addObject(new turtle(), 0, 450);
            getWorld().removeObjects(getWorld().getObjects(Blowfish.class));
            getWorld().removeObjects(getWorld().getObjects(Jellyfish.class));
            getWorld().removeObjects(getWorld().getObjects(Shark.class));
            getWorld().removeObjects(getWorld().getObjects(Eel.class));
            getWorld().removeObjects(getWorld().getObjects(Swordfish.class));
            getWorld().removeObjects(getWorld().getObjects(Ray.class));
            getWorld().removeObjects(getWorld().getObjects(check.class));
            getWorld().removeObjects(getWorld().getObjects(introduction.class));
            getWorld().removeObjects(getWorld().getObjects(controlsicon.class));
            getWorld().removeObject(this);
        }
    }