简单的电话本系统的课程设计，实现了基本的电话本功能，实现了用户登录注册、查询朋友信息、修改密码、添加朋友、查询朋友留言的功能-Simple phone curriculum design of the system to achieve the basic functions of the phone book to achieve a registered user login, query friend information, change passwords, add a friend,