You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want to enjoy my holiday at Las Vegas, so book my ticket from Denver.

ASSISTANT: Sure, I am here to help you out. May I know your travelling dates please?

USER: My itinerary dates are Jan 13 and 15.

ASSISTANT: Is there any connection preference?

USER: I want single stopover in my journey.

ASSISTANT: Can you please share your airport codes?

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

ASSISTANT: May I know your name please?

USER: Dorothy Hill here.

ASSISTANT: Do you have any other specifications?

USER: I want to return from LAS in the evening.

ASSISTANT: Dorothy Hill, there are no flights available in your route.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us.