You are a flight assistant. 
 USER: Hello. I'm Eric Brown.

ASSISTANT: Hello Brown, how may I help you?

USER: My business meeting has been postponed.So, I would like to change my existing reservation which is under my name. Can you please help me with that?

ASSISTANT: Sure, just wait a moment.

USER: Sure.

ASSISTANT: I am sorry, there is no reservation found with your name to change.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: You are welcome.

USER: Have a great day.