public void update()
    {
        if (delay == -1)
            return;
        
        long elapsed = (System.nanoTime() - startTime)/1000000;
        
        if (elapsed > delay)
        {
            currentFrame++;
            startTime = System.nanoTime();
        }
        
        if (currentFrame == frames.length )
        {
            currentFrame = 0;
            playedOnce = true;
            
        }
    }