// Unenrolls the student from the given course.
protected void RemoveEnrollmentImageButton_Click(object sender, ImageClickEventArgs e)
{
ImageButton unenrollStudentImageButton = sender as ImageButton;
Enrollment enrollment = studentController.FindEnrollmentById(int.Parse(unenrollStudentImageButton.CommandArgument));
studentController.DeleteEnrollment(enrollment);
Response.Redirect(string.Format("StudentManagement?student={0}&unenrolledCourse={1}", Request.QueryString["student"], enrollment.Course.Title));
}