You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Due to some urgent meeting, I will change my reservation. Can you please help me for this?

ASSISTANT: Sure, I am here to help you.

USER: Thank you very much for quick access.

ASSISTANT: May I know your name please to check your previous reservation status?

USER: Myself Gregory Carter.

ASSISTANT: Gregory Carter, no reservation has been found on your name in our records.

USER: Not a big problem, anyway thank you very much for your service.

ASSISTANT: Thank you for approaching us.

USER: You are welcome.