You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Rebecca Smith here.

ASSISTANT: How may I assist you at this moment Smith?

USER: I want to attend a Seminar in Chicago. Can you please help me for booking the flight ticket?

ASSISTANT: Sure, I am glad to help you with that. Can you please provide your planned dates of travelling?

USER: My travelling dates are from 08/16 to 08/18.

ASSISTANT: Ok, may I know your preferable origin and destination airport codes for booking?

USER: My airport codes are from DTW to ORD.

ASSISTANT: Please wait a moment to check the flights availability in your route.

USER: Ok, I will wait.

ASSISTANT: We regret to inform you that there are no flights moving to your region with your planned dates of travelling.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for reaching us, hope you have a great day.