You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help?

USER: Helen Carter here. Can you please help me in booking a flight ticket from DEN to LAS?

ASSISTANT: Sure, please provide me your planned travel dates.

USER: Sure, my travel dates are from Mar 21 to Mar 23.

ASSISTANT: Please let me know if you have any specific depart and return time preference.

USER: No, I don't have any specific timings.

ASSISTANT: Do you prefer a halt between your journey?

USER: Yes, I need a connecting flight.

ASSISTANT: Thank you for your details, we have a flight from UA airline, flight number 1015 and the price is 200. Shall I proceed?

USER: Ok, please proceed.

ASSISTANT: Your ticket has been confirmed.

USER: Thank you for booking.

ASSISTANT: Thank you for opting us.