You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: My business meeting has been postponed, so I would like to change my existing reservation.

ASSISTANT: Ok, to proceed further may I know your name?

USER: Sure, my name is Anna Robinson.

ASSISTANT: Sorry, there is no reservation found with your name to change reservation.

USER: Ok, no problem.

ASSISTANT: Thank you for availing us.

USER: Thank you for checking.