You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want to change my reservation, because I have some another important work on those dates so can you please change my reservation?

ASSISTANT: Ok, please provide your name so that I can help you easily.

USER: Sure, my name is Timothy Mitchell.

ASSISTANT: There is no reservation with your name Timothy Mitchell.

USER: Oh! It's ok no problem.

ASSISTANT: Ok, thanks for approaching us.

USER: Thank you for your information.