// 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));
}