You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

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

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

USER: I would like to take off on 06/22 and return on 06/24.

ASSISTANT: Ok, may I know your nearest airport codes for booking?

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

ASSISTANT: Please wait a moment to check the flights availability.

USER: Sure, take your time.

ASSISTANT: Sorry to inform you that, there are no flights available in your travel locations with your requested dates of travelling.

USER: That's ok, I will find an another alternate way to complete my trip. Anyways, thank you for the information.

ASSISTANT: Thank you for reaching us, have a great day.