You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I support you?

USER: I want to change my existing reservation. Can you please help me?

ASSISTANT: Sure, may I know your name to check your ticket from our database.

USER: Thanks for accepting my request, I am Mary Scott.

ASSISTANT: Thanks for providing your information, please wait for a moment.

USER: Sure.

ASSISTANT: We regret to inform you that there is no reservation found on your name to change.

USER: Ok, thanks for your service.

ASSISTANT: Thank you for contacting us.