protected void ValidateInfo_Server(object sender, EventArgs e)
        {
            tbStartDate.Enabled = true;
            tbEndDate.Enabled = true;
            tbTeacher1.Enabled = true;
            tbTeacher2.Enabled = true;

            bool isValidated = true;
            List<string> teachers = new List<string>();

            if (tbCourseName.Text == "" || tbCourseName.Text.Length > 50)
            {
                isValidated = false;
            }

            if (tbTeacher1.Text == tbTeacher2.Text)
            {
                isValidated = false;
            }
            else if (tbTeacher1.Text == "" && tbTeacher2.Text == "")
            {
                isValidated = false;
            }
            else
            {
                if (tbTeacher1.Text != "")
                {
                    teachers.Add(tbTeacher1.Text);
                }
                if (tbTeacher2.Text != "")
                {
                    teachers.Add(tbTeacher2.Text);
                }
            }

            if (tbStartDate.Text == "" || tbEndDate.Text == "")
            {
                isValidated = false;
            }
            else if (DateTime.Parse(tbStartDate.Text) >= DateTime.Parse(tbEndDate.Text))
            {
                isValidated = false;
            }

            if (new Search().GetCourseInfoByName(tbCourseName.Text).ID > 0)
            {
                isValidated = false;
                tbStartDate.Enabled = false;
                tbEndDate.Enabled = false;
                tbTeacher1.Enabled = false;
                tbTeacher2.Enabled = false;
                Response.Write("<script>alert('该课程已存在,请更换');window.location.href='" + Request.RawUrl + "';</script>");
                return;
            }

            if (isValidated)
            {
                CourseInfo course = new CourseInfo(tbCourseName.Text, DateTime.Parse(tbStartDate.Text), DateTime.Parse(tbEndDate.Text));

                Admin admin = new Admin();
                if (admin.AddCourse(course, teachers))
                {
                    FilesCreate(tbCourseName.Text);             // 为新加的课程创建文件夹及文件
                    tbStartDate.Enabled = false;
                    tbEndDate.Enabled = false;
                    tbTeacher1.Enabled = false;
                    tbTeacher2.Enabled = false;
                    Response.Write("<script>alert('添加成功');window.location.href='./Course_Manage.aspx';</script>");
                }
                else
                {
                    tbStartDate.Enabled = false;
                    tbEndDate.Enabled = false;
                    tbTeacher1.Enabled = false;
                    tbTeacher2.Enabled = false;
                    Response.Write("<script>alert('服务器繁忙,请稍后再试');window.location.href='" + Request.RawUrl + "';</script>");
                }

            }
            else
            {
                tbStartDate.Enabled = false;
                tbEndDate.Enabled = false;
                tbTeacher1.Enabled = false;
                tbTeacher2.Enabled = false;
                Response.Write("<script>alert('请按流程输入合理数据');window.location.href='" + Request.RawUrl + "';</script>");
            }
        }