You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: I want to change my existing reservation due to postpone of my board meeting, can you help me with this?

ASSISTANT: Sure, I am here to help you out.

USER: Thank you.

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

USER: My name is Donald Clark.

ASSISTANT: Ok, please give me a moment.

USER: Sure.

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

USER: Not an issue, thank you for the information.

ASSISTANT: Thank you for reaching us.