@Override
  public String execute() {

    DienthoaiDAO dao = new DienthoaiDAO();
    Dienthoai dienthoai;

    if (masanpham == 0) return ERROR;
    dienthoai = dao.getDienthoaiById(masanpham);

    if (dienthoai == null) return ERROR;
    else {
      int q = sl;
      Map session = (Map) ActionContext.getContext().get("session");
      Cart cart;
      cart = (Cart) session.get("cart");
      if (cart == null) {
        cart = new Cart();
        cart.addToCart(dienthoai, q);
        cart.optimizeCart();
      } else {
        cart.addToCart(dienthoai, q);
        cart.optimizeCart();
      }
      System.out.println("soluong = " + q);
      session.put("cart", cart);
      return SUCCESS;
    }
  }
  @Override
  public String execute() throws Exception {
    DienthoaiDAO dao = new DienthoaiDAO();

    System.out.println("inside ViewMobileByPriceAction");
    System.out.println("minPrice = " + minPrice);
    System.out.println("maxPrice = " + maxPrice);

    dienthoais = dao.getDienthoaiByPriceRange(minPrice, maxPrice);
    //		Dienthoai firstOne = dienthoais.get(0);
    //
    //		ValueStack stack = ActionContext.getContext().getValueStack();
    //		Map<String, Object> context = new HashMap<String, Object>();
    //		context.put("firstOne", firstOne);
    //		stack.push(context);

    return SUCCESS;
  }