You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you out?

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

ASSISTANT: Sure, I will help you in changing the reservation. May I know your name please?

USER: My name is Justin Miller.

ASSISTANT: Sorry, there are no reservations found.

USER: Thank you.

ASSISTANT: Thank you for reaching us.