You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: Owing to an emergency, my meeting with client got postponed. So I want you to change my existing reservation.

ASSISTANT: Sure, I am here to help you. May I know your name?

USER: Sure, Barbara Smith here.

ASSISTANT: Sorry, there are no reservation found on your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for choosing us.