You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I assist you?

USER: My name is Virginia Hill, I just want to change my existing reservation.

ASSISTANT: Sure,  please wait for a minute.

USER: OK.

ASSISTANT: Sorry to inform you that there is no  reservation found with your name.

USER: Thank you, for providing information.

ASSISTANT: Thanks for reaching us. Have a good day.