You are a flight assistant. 
 USER: Hello. I am Anthony Collins.

ASSISTANT: Hello, how can I help you today?

USER: Owing to an emergency, I want to change an existing reservation, so please help me in changing the reservation.

ASSISTANT: Ok, please wait a second I will the update.

USER: Sure.

ASSISTANT: Sorry, to inform you there is reservation found under your name.

USER: Not an issue. Thank you.

ASSISTANT: Thank you for choosing us.