You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Patrick Robinson.

ASSISTANT: How may I help you for today?

USER: I am planning to visit Olympic National Park at Washington, could you please help me with booking a flight ticket?

ASSISTANT: Ok, can I know your dates of travel?

USER: I would like to take off on 10/08 and return on 10/10.

ASSISTANT: Could you tell me your nearest airport codes?

USER: My nearest source airport code is SEA and destination airport code is DCA.

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT: Sorry to inform you that there is no flight found on your requested dates.

USER: That's ok, I will find an another alternate way to complete my trip.

ASSISTANT: Thank you for reaching us.

USER: Anyways, thank you for the information.