// add surface charge
        public int addSurface(Desk desk)
        {
            int cost = (int)desk.surface;

            return(cost);
        }
        // add cost for drawers
        public int addDrawers(Desk desk)
        {
            int cost = desk.drawers * 50;

            return(cost);
        }
        public int calcPrice(Desk desk, int rush)
        {
            int cost = addDrawers(desk) + addRush(desk, rush) + addSurcharge(desk) + addSurface(desk);

            return(cost);
        }