You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you for the day?

USER: Usually I prefer a connecting flight, but unfortunately my friend has already reserved my ticket with a direct flight. So, I want to change it. Can you please change my existing reservation?

ASSISTANT: Sure, I am here to help you. May I know your good name?

USER: Sure, I am Mary Martin.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, we found no reservation on your given name.

USER: Ok. Thank you for your help.

ASSISTANT: Thank you for reaching us.