You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I would like to change my existing reservation due to postpone of my seminar. Can you please help me?

ASSISTANT: Sure, I am here to help you. May I know your name to check your previous reservation status?

USER: Sure, Brian Evans here.

ASSISTANT: Ok, please give me a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name in our records.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for choosing us.