You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Can you help me to book a flight ticket from DEN to ORD?

ASSISTANT: May I know your travel dates?

USER: My trip dates are 23 to 25 of Jan.

ASSISTANT: Do you have any connecting flight preferences?

USER: I need a connecting flight.

ASSISTANT: May I know your name please?

USER: I am Brandon Martinez.

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

USER: Oh! that very sad to hear, thank you.

ASSISTANT: Thank you for choosing us.