You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I want to change my reservation, can you help me?

ASSISTANT: Sure. Wait for a moment please.

USER: Ok.

ASSISTANT: May I know your name please?

USER: Myself Robert Roberts.

ASSISTANT: Thanks for waiting. But I am sorry to say that there is no flight reservation on your name to change it.

USER: No problem, thanks for checking.

ASSISTANT: Thank you.