You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Ronald Walker here, I want to change my destination airport code in my existing reservation.Can you please help me out?

ASSISTANT: Ok, please wait for a while.

USER: Sure, take your time.

ASSISTANT: Sorry, no reservation found on your name to change.

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

ASSISTANT: Most welcome.