You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: I am Margaret Walker. Can you please help me with changing my recent reservation.

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Thanks for waiting. But I am sorry to say that there is no flight reservation on your name to change it.

USER: No problem, thanks for the information.

ASSISTANT: Thank you.