Question 28 - 30 refer to following conversation:

Hello, Ms. Gardiner. This is Anthony Costas calling from Europa Travel Agency. (98) As you requested, I changed the date of your Zeus Airlines flight. (99) You'll be taking the flight that departs at 11:35 A.M., instead of the one that leaves at 4:55 PM. Your ticket is still for economy class, and the same baggage allowance applies. You can print your ticket at the airport by using the self- service check-in booths in the departure terminal. (100) However, I'd recommend just checking in on the Zeus Airlines Web site 24 hours before your flight. It's a very quick and convenient process. I hope you have a safe flight and an enjoyable vacation.

28. Why is the speaker calling?