You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: As my business meeting got postponed, can you help me to change my existing reservation?

ASSISTANT: May I know your name please?

USER: Yes, my name is Frank Martinez.

ASSISTANT: OK, please wait for a couple of minutes, I will check and let you know.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry to inform you that there is no reservation found on your name.

USER: OK, thank you.

ASSISTANT: Thank you for choosing us, have a nice day.