You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I want to book a ticket from DFW to DEN. Could you book a ticket?

ASSISTANT: Please share your trip dates?

USER: Departure date is Dec, 23 and return by Dec, 25.

ASSISTANT: Do you have any connecting flight preferences?

USER: I would prefer connecting flight.

ASSISTANT: Is there any other concern?

USER: No.

ASSISTANT: May I know your name please?

USER: My name is Anna Thompson.

ASSISTANT: No flights found as per your preferences at the moment.

USER: Thanks.

ASSISTANT: Thank you for choosing us.