@Override
    public int compare(Unit arg0, Unit arg1)
    {
	if(arg0.getY() < arg1.getY())
	{
	    return -1;
	}
	else if(arg0.getY() == arg1.getY())
	{
	    return 0;
	}
	else if(arg0.getY() > arg1.getY())
	{
	    return 1;
	}
	return -2;
	
    }