// Unenrolls the student from the given course.
        protected void RemoveEnrollmentImageButton_Click(object sender, ImageClickEventArgs e)
        {
            ImageButton unenrollStudentImageButton = sender as ImageButton;
            Enrollment  enrollment = courseController.FindEnrollmentById(int.Parse(unenrollStudentImageButton.CommandArgument));

            courseController.DeleteEnrollment(enrollment);
            Response.Redirect(string.Format("CourseManagement?course={0}&unenrolledFirstName={1}&unenrolledLastName={2}", Request.QueryString["course"], enrollment.Student.FirstMidName, enrollment.Student.LastName));
        }