private void refreshListButton_Click(object sender, EventArgs e)
        {
            // switch to view all students Form
            if (viewStudentForm == null)
            {
                if (mainForm == null)
                {
                    mainForm = new MainForm();
                    mainForm.Show();
                }
                else
                {
                    mainForm.Activate();
                }

                viewStudentForm           = new ViewStudentForm();
                viewStudentForm.MdiParent = mainForm;

                viewStudentForm.FormClosed += delegate(object o, FormClosedEventArgs args) { viewStudentForm = null; };
                viewStudentForm.Show();
            }

            else
            {
                viewStudentForm.Activate();
                viewStudentForm.PopulateListView();
            }
        }
        private void viewAllToolStripMenuItem2_Click(object sender, EventArgs e)
        {
            // view all students
            if (viewStudentForm == null)
            {
                viewStudentForm           = new ViewStudentForm();
                viewStudentForm.MdiParent = this;

                viewStudentForm.FormClosed += delegate(object o, FormClosedEventArgs args) { viewStudentForm = null; };
                viewStudentForm.Show();
            }

            else
            {
                viewStudentForm.Activate();
                viewStudentForm.PopulateListView();
            }
        }