private void cbCourses_SelectedIndexChanged(object sender, EventArgs e) { lbStudents.Items.Clear(); string id = cbCourses.SelectedItem.ToString(); foreach (Course c in courses) { if (c.CourseID.Trim() == id.Trim()) { this.txtName.Text = c.CourseName; this.txtCost.Text = c.Cost.ToString("C"); } } Tafe_DataTier dt = new Tafe_DataTier(); List <Student> students = dt.getStudentEnrolledInCourse(id); if (students.Count == 0) { lbStudents.Items.Add("--------- NO ENROLLMENTS ----------"); } else { foreach (Student s in students) { this.lbStudents.Items.Add(s.StudentName + " --> " + s.StudentID); } } }