anchor.diff:      double _subTotal;
   
     //update items in the shopping cart
  -    void update(int itemCode, int qty, double perItemCost) {
  +    void update(int itemCode, int iQty, double perItemCost) {
         this.itemCode = itemCode;
  -      this.qty =qty;
  +      this.iQty = iQty;
         this.perItemCost = perItemCost;
       }
   
  
positive.code:   ''');
    var str = request.headers.toString();
    for (int i = 0; i < str.length - 1; i++){
      if (str[i] == "\n") { sb.write("\n  ");
      } else { sb.write(str[i]);
      }
    }
    sb.write('''\nrequest.session.id : ${request.session.id}
  requset.session.isNew : ${request.session.isNew}''');
    if (request.method == "POST") {
      var enctype = request.headers["content-type"];
      if (enctype[0].contains("text")) {
  
negative.code: 
    Map<int, ShoppingCartItem> get items => _items;
  
    final List lMenu = [
      300, "Tai (Japanese red sea bream)", 3.60,
      290, "Maguro (Tuna)", 3.60,
      280, "Sake (Salmon)", 3.60,
      270, "Hamachi (Yellowtail)", 3.60,
      260, "Kanpachi (Great amberjack)", 3.60,
      150, "Tobiko (Flying Fish Roe)", 5.20,
      160, "Ebi (Shrimp)", 2.40,
      170, "Unagi (Eel)", 5.20,
      180, "Anago (Conger Eal)", 3.60,
      190, "Ika (Squid)", 2.00
    ];
  
    // constructor
    TodaysMenu() {
      for (var i = 0; i < lMenu.length ~/ 3; i++) {
        var cartItem = new ShoppingCartItem();
        cartItem.itemCode = lMenu[i * 3];
        cartItem.itemName = lMenu[i * 3 + 1];
        cartItem.perItemCost = lMenu[i * 3 + 2].toDouble();
        cartItem.iQty = 0;
        cartItem.subTotal = 0.0;
        _items[cartItem.itemCode] = cartItem;
      }
    }
  }
  
  // Create menu page HTML text.
  StringBuffer createMenuPage({ShoppingCart cart: null}) {
  