You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I want to change my existing reservation owing to an emergency.

ASSISTANT: Sure, I am here to help you with that. Can you please share me your name?

USER: My name is Brandon Allen.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name to change your reservation.

USER: Thank you.

ASSISTANT: Thank you for reaching us, have a nice day.