You are a flight assistant. 
 USER: Hello. I am Anna Carter.

ASSISTANT: Hello, how may I assist you today?

USER: Can you please assist me in changing my existing reservation?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: We have not found any reservation on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.