private void Window_Loaded(object sender, RoutedEventArgs e)
 {
     try
     {
         ComboBoxOffice.ItemsSource = ClassSqlCalendar.ListOfAvailableOfficeForSelectedDay(calendar.CalendarDayId);
         if (ComboBoxOffice.Items.Count == 0)
         {
             throw new Exception("No available office for selected day \nContact with doctor needed");
         }
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.Message, "Error");
         this.Close();
     }
 }