public boolean isFull()
    {
        boolean full = true;
        for (int x=0; x<3; x++)
        {
            for (int y=0; y<3; y++)
            {
                int[] pos = { x, y };
                Player curr = getPlayerAtPosition(pos);
                if(curr==null)
                {
                    // Empty spot
                    full=false;
                    break;
                }
            }
            if (!full)
            {
                break;
            }
        }
        return full;
    }