You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

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

ASSISTANT: Let me know your name.

USER: My name is Katherine King.

ASSISTANT: Sorry, no reservation found by your name.

USER: That's ok, thank you for the response.

ASSISTANT: Thank you.