You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Owing to emergency, I requesting you to change my existing reservation.

ASSISTANT: Ok, firstly let me check your reservation status. May I know your good name please?

USER: My good name is Mark Evans.

ASSISTANT: Ok, please be on hold.

USER: Sure.

ASSISTANT: Evans, there is no reservation found under your name to do changes in that.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for choosing us.