You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Joseph Wilson.

ASSISTANT: How can I aid you?

USER: I would like to change my reservation, could you help me out?

ASSISTANT: Sure, I am glad to help you in modifying your reservation.

USER: That's great.

ASSISTANT: Please allow me a moment to check for your previous reservation status.

USER: Take your time.

ASSISTANT: Thank you for waiting.

USER: Please don't waste my time.

ASSISTANT: Sorry to say, there is no active reservation have been found under your name in our database to amend it.

USER: That's ok.'.

ASSISTANT: Thank you for opting us.

USER: Thank you for your time.