You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Mark Robinson here. I want to celebrate my birthday in Las Vegas, could you book my ticket from Denver?

ASSISTANT: Sure, let me know your travelling dates.

USER: My itinerary dates are Feb 18 and Feb 20.

ASSISTANT: Can you please share your airport codes?

USER: My genesis and terminus airport codes are DEN and LAS.

ASSISTANT: Do you have any other specifications?

USER: I need a connecting flight.

ASSISTANT: We found an UA airlines with single connection and flight number is 1013. Shall I proceed?

USER: Please proceed.

ASSISTANT: Your ticket has been confirmed.

USER: Thank you for your service.

ASSISTANT: Thank you.