You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Gregory Adams.

ASSISTANT: How can I assist you now?

USER: 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 in booking the flight ticket. Can you please mention the travelling dates of your journey?

USER: I would like to take off on 03/20 and return on 03/22.

ASSISTANT: Ok, may I know the airport codes please?

USER: My source airport code is HOU and destination airport code is IAD.

ASSISTANT: Please wait for a moment.

USER: Sure, take your time.

ASSISTANT: Sorry Gregory, there are no flights found on your requested dates.

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

ASSISTANT: Thank you for approaching us, have a nice day.

USER: Anyways, thank you for the information.

ASSISTANT: You are welcome.