You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I have made an earlier reservation to attend for an conference, due to some issues conference has been postponed. Can you please help me to change it?

ASSISTANT: May I know your name please?

USER: Sure, my name is James White.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name to change.

USER: Ok, thanks for your information.

ASSISTANT: Thank you for reaching us.