Declines an appointment, task, or note, and attaches a comment.
AFTKN_ITEM_DECLINE or 788
VOID ItemDecline([ANSISTRING Comment]; [ANSISTRING MessageID]; [ENUM AllInstances])
(Optional) Comment is displayed in an item's information view.
(Optional) Unique item identifier, returned by ItemMessageIDFromView(). If not specified, declines the selected item.
(Optional)