You are a flight assistant. 
 USER: Hello, I am Emily White.

ASSISTANT: Hello, how may I assist you?

USER: I want to change my existing reservation due to postpone of my friend marriage. Can you please help me with this?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Emily White, there is no reservation on your name.

USER: No problem, thanks for your information.

ASSISTANT: Thank you.