You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Anthony Walker, I want to change my reservation which is existing under my name.

ASSISTANT: How can I help you? On which name can I proceed for changing?

USER: I have mentioned above.

ASSISTANT: I am sorry no reservation found on your name.

USER: It's ok, anyway thank you for the information.

ASSISTANT: Thank you for choosing us.