You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Can you please change my existing reservation?

ASSISTANT: Sure,I can change your reservation right now. Before that I need to know your good name please?

USER: Sure, I am Raymond Williams.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there are no active reservations on your given name to change.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching our service.