You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, do you need any help from us?

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

ASSISTANT: Ok, could you please share your departure and arrival day?

USER: I want to travel on 11/10, and return on 11/12.

ASSISTANT: Ok, could I have your name please?

USER: I am Paul Green.

ASSISTANT: Ok, do you need direct or connecting flight?

USER: I need a direct flight.

ASSISTANT: Ok, do you have any other specifications?

USER: No.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: Ok, no problem. Thanks for the information.

ASSISTANT: You are welcome, have a great day.