You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: My business meeting has been postponed.Can you please help me for changing an existing reservation?

ASSISTANT: Ok, may I know your name please?

USER: Sure, my name is Matthew Jackson.

ASSISTANT: Ok Matthew, sorry for inconvenience, no reservation found for you.

USER: Ok, It's fine. Thank you for your information.

ASSISTANT: Thanks for receiving us, have a great day.

USER: You are welcome.