You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I am Katherine White. Owing to an emergency, I want to change an existing reservation.

ASSISTANT: Sure, could you please hold a moment, let me check your reservation with us.

USER: Sure.

ASSISTANT: Thanks for holding on, sorry, unfortunately no reservation found with provided name.

USER: Not an issue. Thanks for your service.

ASSISTANT: Thanks for your interest, have a good day.