You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

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

ASSISTANT: Sure, may I know your name please to check the reservation status?

USER: Sure, my name is Jack Lewis.

ASSISTANT: Jack, there is no reservation found with your details.

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

ASSISTANT: Thank you for choosing us, have a good day.