You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I be your helping hand?

USER: I am Brian Allen. I need to change my recent reservation due to postpone of my seminar. Could you please help me in doing that?

ASSISTANT: Ok. I will help you.

USER: Thank you.

ASSISTANT: Please wait for a moment, I will check your previous reservation.

USER: Sure.

ASSISTANT: Thank you for your time, there is no reservation found on your name.

USER: No worries, thank you for your information.

ASSISTANT: Thank you for approaching us.