public static string EnrollCourse(string[] cid, int credithours)
    {
        string result = "";
        
        DBFunctions db = new DBFunctions();
        for (int i = 0; i < cid.Length;i++)
        {
            Enroll_Course enroll = new Enroll_Course { CourseID = Convert.ToInt16(cid[i]), Uid = uid, Status = 0 };
            db.Enrollcourse(enroll);
        }
        StudentSelectedCredit obj = db.getStudentCredits(uid).FirstOrDefault();
        if (obj == null)
        {
            StudentSelectedCredit temp = new StudentSelectedCredit();
            temp.UserID = uid;
            temp.SelectedCourseCount = credithours;
            int check = -1;
            check = db.AddCreditHours(temp);
            if (check != 1)
            {
                result = "Success";
            }
        }
        else
        {

            StudentSelectedCredit temp = new StudentSelectedCredit();
            temp.UserID = uid;
            temp.SelectedCourseCount = credithours;
            temp.ID = obj.ID;
            db.UpdateCreditHours(temp);
        }
       return result;
    }
    public static string EnrollCourse(string[] cid, int credithours)
    {
        string result = "";

        DBFunctions db = new DBFunctions();

        for (int i = 0; i < cid.Length; i++)
        {
            Enroll_Course enroll = new Enroll_Course {
                CourseID = Convert.ToInt16(cid[i]), Uid = uid, Status = 0
            };
            db.Enrollcourse(enroll);
        }
        StudentSelectedCredit obj = db.getStudentCredits(uid).FirstOrDefault();

        if (obj == null)
        {
            StudentSelectedCredit temp = new StudentSelectedCredit();
            temp.UserID = uid;
            temp.SelectedCourseCount = credithours;
            int check = -1;
            check = db.AddCreditHours(temp);
            if (check != 1)
            {
                result = "Success";
            }
        }
        else
        {
            StudentSelectedCredit temp = new StudentSelectedCredit();
            temp.UserID = uid;
            temp.SelectedCourseCount = credithours;
            temp.ID = obj.ID;
            db.UpdateCreditHours(temp);
        }
        return(result);
    }