You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I want to change my existing reservation due to some bad weather conditions. Can you please help me in that?

ASSISTANT: Sure, I am glad to help you out.

USER: Thank you.

ASSISTANT: Let me know your name to check your previous reservation status.

USER: Myself Alexander Jackson.

ASSISTANT: Ok, please give me a moment.

USER: Sure.

ASSISTANT: Thank you for waiting. Sorry to inform you that, there is no reservation done on your name in our data base to modify it.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for approaching us.