You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Gary White.

ASSISTANT: How can I assist you today?

USER: Would it be possible to change my reservation, which I have my reservation before two months back.

ASSISTANT: Sure, will you please give me a moment?

USER: Sure.

ASSISTANT: Thanks for waiting, there is no reservation found under your name.

USER: It's ok, thanks for your information.

ASSISTANT: Welcome, have a great day.