You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I give assistance to you?

USER: I want to change my reservation as my plan to visit New York to meet my brother is postponed. Can you change my reservation?

ASSISTANT: Sure, we are glad to assist you to change it.

USER: Ok.

ASSISTANT: Can please provide your name to check with your previous reservation?

USER: I am Joseph Wright.

ASSISTANT: Thanks for providing your name, please wait for a while.

USER: Sure.

ASSISTANT: Sorry to inform you that, there was no active reservation found on your name to change it.

USER: That's ok, thank you.

ASSISTANT: Thank you for opting our service.