说明：  网上选课系统主要是实现了管理员管理系统，参数设置,帐号管理,学科管理等；教师查看学生的选课信息，登录成绩等；学生进行选课，对所选课程进行删除，成绩查询等功能。都需要身份验证才能进入系统，需要用户账号密码和用户类型填写正确才能进入系统，否则会有错误提示。
(Online course selection system is to achieve administrators to manage the system, parameter settings, account management, discipline management, etc. teachers view the students' course selection information, log results students in course selection, to delete the selected course, result inquiry function. Authentication is required to enter the system, you need the user account password and user type to fill in the correct order to enter the system, otherwise there will be errors.)