public boolean hasSelectedCourse(String courseID, int year, int term) {
		for(ConcreteCourse course:this.selectedCourses){
			if(course.getCourseID().equals(courseID)&&course.getTerm()==term&&
					course.getYear()==year)
				if(course.hasSelectedStudent(studentID))
					return true;
		}
		return false;
	}