public void removeStd(string username, ref courseDatabase crsDB)
        {
            student std = getStudent(username);

            // Increment the number of seats available for each course the student has registered for
            List <course> registeredCrsLst = std.registeredCrs;

            foreach (course registeredCrs in registeredCrsLst)
            {
                foreach (course crs in crsDB.getCourseList())
                {
                    if (registeredCrs.crsID == crs.crsID)
                    {
                        crs.disenrollUser(std);
                        break;
                    }
                }
            }

            // Remove the student from the advisees list of his advisor
            faculty advisor = getFaculty(std.advisor);

            advisor.removeAdvisee(username);

            // Remove the student from the database
            stdLst.Remove(std);
        }
        public void changeAdvisor(string stdName, string facName)
        {
            // Change the student's advisor
            student std        = getStudent(stdName);
            string  curAdvisor = std.advisor;

            std.setAdvisor(facName);

            // Add the student to the new faulty's advisee list
            faculty fac = getFaculty(facName);

            fac.addAdvisee(std);

            // Remove the student from the previous faculty's advisee list
            fac = getFaculty(curAdvisor);
            fac.removeAdvisee(stdName);
        }