You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What assistance you are looking from us?

USER: I want to change an existing reservation, so please help me in changing the reservation.

ASSISTANT: Ok, I am here to help you with that.

USER: Thank you.

ASSISTANT: May I know your name?

USER: Myself Edward White.

ASSISTANT: Please give me a second.

USER: Ok.

ASSISTANT: Sorry to say that, there is no reservation found on your name in our database.

USER: Not an issue. Thank you for your information.

ASSISTANT: Thank you for approaching us.