You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I want to change my destination airport code in my existing reservation, can you please help me out?

ASSISTANT: Sure, may I know your name?

USER: Sure, my name is Matthew Davis.

ASSISTANT: Please wait a moment.

USER: Ok, take your time.

ASSISTANT: Sorry, there are no active reservations on your name to change.

USER: It's ok, thank you for the information.

ASSISTANT: Thank you our reaching our service.