You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation, my music concert got postponed. Can you please help me out with that?

ASSISTANT: Sure, may I know your name?

USER: Thank you, my name is Donald Perez.

ASSISTANT: Wait a minute.

USER: Sure, take your time.

ASSISTANT: We found your reservation, can you please let us know your travelling dates?

USER: Sure, I am planning to move on Apr 14 and please book my return ticket on Apr 16.

ASSISTANT: May I know your source and destination points?

USER: Sure, I want to travel from IAH to OFK.

ASSISTANT: Do you have any other preferences?

USER: I would prefer connecting flight for my journey.

ASSISTANT: Can you please re-check your destination code?

USER: Sorry, my destination airport code is OAK.

ASSISTANT: There is a flight of frontier airline, flight number 1023 with the fare of 200. Shall I proceed?

USER: I am ok with this flight, you can proceed with booking now.

ASSISTANT: Your ticket has been booked.

USER: Thank you for your assistance.

ASSISTANT: Thank you for choosing us.