protected virtual void PrintSchedule_button_Click(object sender, EventArgs e)
 {
     if (ScheduleSQL.SearchSchedule(this.teachingAssist.Id) == false)
     {
         MessageBox.Show("No schedule has been assigned yet.");
     }
 }
 protected override void PrintSchedule_button_Click(object sender, EventArgs e)
 {
     if (ScheduleSQL.SearchSchedule(this.lecturer.Id) == false)
     {
         MessageBox.Show("No schedule has been assigned yet.");
     }
 }