You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I help you?

USER: I am Betty Nelson. I want to change my existing reservation.

ASSISTANT: Thank you for providing your name, Can you please wait a minute, so that I will check the existing reservation and get back to you?

USER: Sure,That's OK.

ASSISTANT: Thank you for being patient, We found no reservation with your specified name.

USER: OK, thank you for your information.

ASSISTANT: Thank you for choosing us, Have a happy day.

USER: Thank you.