You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you today?

USER: I am planning to meet my friend at Washington, will you help me in booking the flight ticket from LAS to IAD?

ASSISTANT: Sure, please share your trip dates.

USER: My preferable journey dates are Oct 13 and Oct 15.

ASSISTANT: Is there any airline preference?

USER: I am comfortable in any airlines.

ASSISTANT: Any other requirement to be met?

USER: I prefer to travel in direct flight.

ASSISTANT: Can you mention your name to proceed further?

USER: Myself Dorothy Clark.

ASSISTANT: Sorry, no flights found as per your requirement.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for contacting us.