private void TeachingAssistant_Menu_Click(object sender, EventArgs e)
{
this.teachingAssistForm = new TeachingAssist_Form();
this.Hide();
teachingAssistForm.FormClosed += new FormClosedEventHandler(teachingAssistForm_FormClosed);
teachingAssistForm.ShowDialog();
}
private void teachingAssistForm_FormClosed(object sender, FormClosedEventArgs e)
{
this.teachingAssistForm.Close();
this.teachingAssistForm = null;
this.Show();
}