You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, What kind of help are you expecting from our side?

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

ASSISTANT: Sure, I can change your reservation right now. Before that I need to know your good name please?

USER: Myself Donald Miller.

ASSISTANT: Ok, wait for some time I will check the reservation on your name and get back to you.

USER: Ok.

ASSISTANT: We are sorry to say that, there is no active reservation found on your name.

USER: Not an issue. Thank you.

ASSISTANT: Thanks for approaching us, wish you a great day.