.FUNCTION....: Act_On_Reservation
.SOURCE......:
.DESCRIPTION.:
When a copy of an item becomes available for members having a
reservation on that item, this function:
- finds the member with the earliest reservation.
- generates text of the letter informing the reserving member
that a copy of the item he reserved is now available. This text
will be sent to the Letter_Lister function which will print the
letter and send it to the member.
- deactivates the reservation, since it has been acted upon.
- informs the Member and Item model processes that this
reservation has been deactivated.
.COMPOSITION.: item_id &item_id