You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

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

ASSISTANT: Ok. Please wait for a minute.

USER: Sure.

ASSISTANT: Thanks for waiting, no reservation was found on the name of Katherine Anderson.

USER: Not an issue. Thank you.

ASSISTANT: Thank you for choosing us.