/// <summary>
        /// Called when the cancel button is pressed.  This discards any changes made to
        /// the data objects.
        /// </summary>
        protected internal override void cancel()
        {
            StateMod_InstreamFlow isf = null;
            int size = _data.Count;

            for (int i = 0; i < size; i++)
            {
                isf = (StateMod_InstreamFlow)_data[i];
                isf.restoreOriginal();
            }
        }