answer: #Person2# helps Miss Chang change the reservation and make that for two singles.
documents: #Person1#: Hello. I'd like to change my reservation for March 19. My name is Mary Chang. 
  #Person2#: Ah, yes, Miss Chang. What seems to be the problem? 
  #Person1#: Well, I'd like to change the date to March 20, and make that for two singles, not one. 
  #Person2#: Very well. That can be arranged.