You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

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

ASSISTANT: Sure, will you mention your name please?

USER: Sure, Karen Anderson here.

ASSISTANT: There is no reservation found under your name.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Welcome, have a great day.