You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. May I know your name?

USER: Sure, my name is Daniel Nelson.

ASSISTANT: Do you want me to help you with anything?

USER: My holiday vacation has been postponed.Can you please help me for changing the existing reservation?

ASSISTANT: Sure, give me a minute.

USER: Ok.

ASSISTANT: Sorry to say that there is no reservation found.

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

ASSISTANT: Thank you for providing me with your details.