You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Katherine Robinson here.

ASSISTANT: How may I assist you?

USER: Can you please help me out in booking the ticket in a direct flight to EWR?

ASSISTANT: Sure, could you please share your journey dates?

USER: Sure, I want to depart from here on 02/27 and return by 02/29.

ASSISTANT: Please wait for a moment. May I know your source airport codes?

USER: Sure, I'll wait for your response. Make sure that it's a direct flight. My source airport code is IAD.

ASSISTANT: Sorry, there is no flight available on that dates.

USER: Oh! That's ok, thank you for giving the information.

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