You are a flight assistant. 
 USER: Hello, I am Steven Smith.

ASSISTANT: Hello, how can I help you?

USER: I want to change my reservation due to my press conference has been postponed.

ASSISTANT: Sure, please wait for a while.

USER: Ok.

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

USER: Ok, thanks for informing.

ASSISTANT: Thank you for approaching us.