You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I am Charles Phillips. 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 with that. Can you please share your your journey dates?

USER: I would like to take off on 11/09 and return on 11/11.

ASSISTANT: May I know your airport codes to proceed further?

USER: My nearest source airport code is OAK and destination airport code is IAD.

ASSISTANT: Wait for a minute.

USER: Sure, take your time.

ASSISTANT: I am sorry to say that there is no flight found under your details.

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.