private void makeCustomer(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String email = request.getParameter("email");
        String username = request.getParameter("username");
        String password = request.getParameter("password");

        d.createCustomer(email);
        d.createUser(username, password, email);

        request.getRequestDispatcher("index.jsp").forward(request, response);
    }