You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I want to change my existing reservation due to postpone of my seminar.

ASSISTANT: May I know your name?

USER: I am Rachel Smith.

ASSISTANT: Please wait.

USER: Sure.

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

USER: No worries, thank you for the information.

ASSISTANT: Thank you for reaching us.