You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I assist you?

USER: I would like to change my existing reservation, due to postpone of my business meeting.

ASSISTANT: Sure, May I know your name?

USER: Barbara Harris.

ASSISTANT: Please wait a second.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for availing us.