// METHODS RELATED TO EXTRAS:

        /*
         * Refreshes the extras fields displayed in the window.
         */
        private void refreshExtrasDisplay()
        {
            if (mFacade.IsABookingLoaded())
            {
                lstExtras.Items.Clear();
                foreach (String s in mFacade.GetCurrentExtrasNames())
                {
                    lstExtras.Items.Add(s);
                }
            }
        }