You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

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

ASSISTANT: Sure, may I know your name?

USER: I am Rebecca Jackson.

ASSISTANT: Give me a minute.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found under your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for opting us.