You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I  help you?

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

ASSISTANT: Just a moment please.

USER: Ok.

ASSISTANT: I am sorry no reservation found on your name.

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

ASSISTANT: Thank you for choosing us.