You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you today?

USER: Can you help me to book a flight ticket from LAS to IAD?

ASSISTANT: Sure, I will help you with that. Can you please provide your preferable dates of travelling?

USER: My travel dates are Jan 14 and Jan 16.

ASSISTANT: Do you have any connection limit?

USER: I prefer direct flight for this trip.

ASSISTANT: Any more specifications do you have?

USER: I would like to prefer economy class flight ticket.

ASSISTANT: On whose name I have to book the flight ticket?

USER: Larry Baker.

ASSISTANT: Please wait a moment to check the flights.

USER: Sure.

ASSISTANT: We are apologize that, there are no direct flights running towards your region with your requested dates of travelling.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for approaching us.