You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to book a flight ticket from DC to visit Olympic National Park in Oakland. Could you please help me to book a flight ticket with single connection?

ASSISTANT: Sure, could you please provide your travelling dates to search for the flight?

USER: I want to reach CA on June 24th and I'll return within two days that is on June 26th.

ASSISTANT: May I know your name?

USER: I am Nicholas Taylor.

ASSISTANT: May I know your source airport code?

USER: I want to start my journey from IAD.

ASSISTANT: Do you have any requirements?

USER: No more retirements, please go with the above details.

ASSISTANT: Sorry to say, no flight is available for you as per your requests.

USER: That's ok, I'll choose any alternative to reach my destination.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your information.