You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

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

ASSISTANT: Sure, can you please provide me your name?

USER: Sure, Brian Nelson here.

ASSISTANT: Sorry, there is no reservation with your given name.

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

ASSISTANT: Thank you for reaching us.