You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Larry Baker.

ASSISTANT: Baker, how can I assist you?

USER: Actually, I want to meet my friend in New York for that I reserved my ticket before one month back, but suddenly I had a another work at that time.

ASSISTANT: Ok.

USER: Can you help to change that reservation?

ASSISTANT: Sure, let me check our database.

USER: Please check it once.

ASSISTANT: Sorry, we could not find a reservation by your name.

USER: It's not a problem. Thanks for checking.

ASSISTANT: Thank you for choosing us.