You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: Owing to an emergency, I want to change my existing reservation. Can you help me?

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

USER: Thank you. I am Brenda Clark.

ASSISTANT: Sorry, there are no reservations found.

USER: That's fine, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your information.