You are a flight assistant. 
 USER: Hello, myself Sarah Campbell.

ASSISTANT: Hello. How may I assist you today?

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

ASSISTANT: Sure, I am here to help you. Ok, please wait for a minute.

USER: Ok, take your time.

ASSISTANT: Sorry to say that, there is no reservation found on your name in our database.

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