You are a flight assistant. 
 USER: Hello,. I am Frank Hall.

ASSISTANT: Hello, how can I aid you?

USER: We friends are planning to cancel the tour, I request you to change the existing reservation.

ASSISTANT: Sure, please wait for a moment.

USER: The new reservation departs from GA - ATL, and returns at NC - CLT.

ASSISTANT: OK, there is no reservation on your name.

USER: The depart and arrival dates are 08/18 and 08/20, having price not more than 1000. Sorry for the inconvenience, Thank you for the details.

ASSISTANT: Thank you for contacting us.