You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I want to change my existing reservation due to postpone of my event.

ASSISTANT: Sure, we are here to help you. Can I have your name to proceed further?

USER: I am Stephen Roberts.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

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

USER: No worries, thank you for the information.

ASSISTANT: Thank you for reaching us.