You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Jonathan Rodriguez.

ASSISTANT: How can I assist you today?

USER: Can you please assist me in reserving a flight ticket from Dallas & Fort Worth to Chicago?

ASSISTANT: Sure, I'm glad to help you with that. May I know your source and destination airport codes please?

USER: Thank you for accepting my request. The source and destination airport codes are DFW and ORD.

ASSISTANT: Sure, may I know your planned travel dates please?

USER: The planned trip dates are Mar 16 and Mar 18.

ASSISTANT: Ok, do you have any other specifications please?

USER: Yes, I need an economy class flight.

ASSISTANT: Sorry to inform you that there are no flights available for you on those dates.

USER: It's ok, not a problem with that. Anyways thank you for your time.

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

USER: You are welcome.