You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: Could you please change my existing reservation due to postpone of my trip?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

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

USER: My name is Paul White.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Paul White, no reservation has been found on your name in our records.

USER: Not a problem, thanks for cheking.

ASSISTANT: Thank you for choosing us.