You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I be of your assistance?

USER: I am a journalist, I want to collect some data from library of congress. But my project dates were postponed.

ASSISTANT: Ok.

USER: Can you help me out in changing my existing reservation?

ASSISTANT: Sure, I am glad to help you.

USER: Thank you.

ASSISTANT: May I know your good name for further process?

USER: Sure, I am William Phillips.

ASSISTANT: Thanks for the information, Wait for a while.

USER: Sure, take your time.

ASSISTANT: Thanks for your patience.

USER: Ok.

ASSISTANT: There is a reservation found with your name, Can your share your new journey dates?

USER: Sure, my new journey dates are from 06/12 to 06/14.

ASSISTANT: May I know your source and destination?

USER: My source is New York, NY - JFK and my destination is Atlanta, GA - ATL.

ASSISTANT: Ok, Please stand by.

USER: Ok.

ASSISTANT: Thanks for your valuable time. I regret to inform you that, there is no flights available with your details.

USER: Ok, not an issue.

ASSISTANT: Thank you for picking us.

USER: Thank you for your information.

ASSISTANT: Have a great day!.