void drawCard(Graphics g, Card card, int x, int y) {
          int cx;
          int cy = 0;
         if (card == null) {  
             cx = 4 * 123;
             cy = 2 * 79;
         }
         else {
             cx = (card.getValue()-1)*79;
             switch(card.getSuit()) {
                 case Card.CLUBS:
                     cy = 0;
                     break;
                 case Card.DIAMONDS:
                     cy = 123;
                     break;
                 case Card.HEARTS:
                     cy = 2 * 123;
                     break;
                 case Card.SPADES:
                     cy = 3 * 123;
             }
             g.drawImage(cardImages, x, y, x+79, y+123, cx, cy, cx+79, cy+123, this);
         }
      } // end drawCard()