You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I would like to change my destination airport code, please help me in changing my existing reservation.

ASSISTANT: Just a moment please.

USER: Sure, take your time.

ASSISTANT: May I know your name please?

USER: My name is Nancy Perez.

ASSISTANT: I am sorry no reservation found on your name.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.