You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: Please book a flight ticket from DFW to ORD.

ASSISTANT: Is there any airline preference?

USER: No.

ASSISTANT: Please provide your journey dates?

USER: My trip dates are 08/26 and 08/28.

ASSISTANT: Do you have any preferences?

USER: I need a direct flight.

ASSISTANT: May I know your name?

USER: Stephanie Brown here.

ASSISTANT: Sorry currently there are no flights for your travelling dates.

USER: That's ok, thank you for the information.

ASSISTANT: Thank you.