      equalTo: icon + "两次输入的密码不一致"
                },
                email: icon + "请输入您的E-mail"
            }
        });

        $("#username").focus(function () {
            var firstname = $("#firstname").val();
            var lastname = $("#lastname").val();
            if (firstname && lastname && !this.value) {
                this.value = firstname + "." + lastname;
            }
        });
    });
    </script>
</body>
</html>
