//Function: modify the arrive time of the reservation
 //    invoked when the reservation becomes TIMEOUT and the manager helps to delay the available time for this reservation
 //$resrvation timeout后,manager可以给延时,状态从timeout到reserved 这个是后加的,设计的有问题,转换写死到数据库存储过程了
 public void ProlongReservation(Guid pId, DateTime pDateTime)
 {
     DataContextDataContext dc = new DataContextDataContext();
     dc.prolong_reservation(pId, pDateTime);
 }