You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

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

ASSISTANT: Sure, may I know your name please to proceed for booking.

USER: I am Robert Thomas.

ASSISTANT: Ok. No reservation found in our database, Robert Thomas.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.