You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I am Barbara Moore. Owing to an emergency, I want to change an existing reservation, so please help me in changing the reservation.

ASSISTANT: Give me a moment please.

USER: Sure.

ASSISTANT: Thanks for your time, there is no reservation found on your name to change it.

USER: Not an issue. Thank you.

ASSISTANT: Thanks for choosing us, have a good day.