You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

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

ASSISTANT: Sure, we are here to help you. May I know your name?

USER: Myself Christopher Martinez.

ASSISTANT: Ok, wait for some time.

USER: Ok.

ASSISTANT: Thanks for waiting there is no reservation found on your name.

USER: Not an issue. Thank you.

ASSISTANT: Thanks for approaching us.