You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I'm Nancy Hill.

ASSISTANT: How may I assist you?

USER: I had planned to go on a vacation, but it was postponed.Can you change my recent reservation?

ASSISTANT: Sure, please give me a minute.

USER: Ok.

ASSISTANT: Sorry, there is no flight available under your name.

USER: That's Ok.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.

ASSISTANT: Have a great day.