public class Explosion extends Actor
{
    GreenfootImage explode1 = new GreenfootImage("exp1.png");
    GreenfootImage explode2 = new GreenfootImage("exp2.png");
    GreenfootImage explode3 = new GreenfootImage("exp3.png");
    GreenfootImage explode4 = new GreenfootImage("exp4.png");
    GreenfootImage explode5 = new GreenfootImage("exp5.png");
    GreenfootImage explode6 = new GreenfootImage("exp6.png");
    GreenfootImage explode7 = new GreenfootImage("exp7.png");
    
    public int animationCounter = 0;
    public int frame = 1;

public void act() 
    {
        animationCounter = animationCounter +1;
        
        if(animationCounter % 6 == 0);
        {
            animation();
        }
        
        
    }    
    
    public void animation()
    {       
        if(frame == 1)
        {
            setImage(explode1);
            frame = 2;
        }
        else if(frame == 2)
        {   setImage(explode2);
            frame = 3;
       
        }
        else if(frame == 3)
        {   setImage(explode3);
            frame = 4;
       
        }
        else if(frame == 4)
        {   setImage(explode4);
            frame = 5;
       
        }
        else if(frame == 5)
        {   setImage(explode5);
            frame = 6;
       
        }
        else if(frame == 6)
        {   setImage(explode6);
            frame = 7;
       
        }
        
        else if(frame == 7)
        {   
            getWorld().removeObject(this);       
        }
    }