modify the Product/add.jsp.
modify the index.jsp
modify the user/login.jsp
modify the ProductServlet.java.
modify the UserServlet.java.
modify the ProductDao.java.
modify the UserDao.java.
modify the Product.java.
modify the ProductService.java.
modify the UserService.java.
modify the Constants.java.
modify the PageUtil.java.
modify the ResponseUtil.java.