You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Can you please help me in booking a flight ticket from LAS to DCA?

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

USER: Sure, my travel dates are from May 14 to May 16.

ASSISTANT: Let me know your connection limit.

USER: I need a direct flight.

ASSISTANT: Do you have any other specifications?

USER: I would like to return in the evening.

ASSISTANT: Please, provide me your name to proceed further.

USER: Myself Sharon Thomas.

ASSISTANT: Ok, be on hold.

USER: Sure.

ASSISTANT: Sorry to say that, there are no flights available as per your specifications.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: My pleasure.