void tb_MouseDown(object sender, MouseButtonEventArgs e)
        {
            Classroom c = (Classroom)((TextBlock)sender).Tag;

            father.SetClassroom(c.cId);
            this.Close();
        }
 private void TBclassroom_MouseDown(object sender, MouseButtonEventArgs e)
 {
     father.SetClassroom(rent.cId);
     if (rent.Time.OnceActivity)
     {
         father.GotoDateClass(rent.Time.StartDate, rent.Time.StartClass);
     }
     this.Close();
 }