dialogue: Grayson: Hey, dad! :) Could you give me a lift to the airport?
  Harrison: when?
  Grayson: Tomorrow.  I have to check in two hours before the flight, so I should be in the airport around 4 pm.
  Harrison: i'm at work at this time
  Harrison: ask your mother
  Harrison: where are you flying to? for how long?
  Grayson: I'm going to Spain for 2 weeks. :)
  Harrison: have fun and don't forget to send me a postcard :-]
  Harrison: don't drink too much
  Grayson: Thanks, dad, I won't! :)
summary: Grayson is going to Spain for two weeks and has to be at the airport at about 4 pm tomorrow. Harrison cannot give his son a lift because he is at work then.