You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

USER: Katherine Taylor here. I want to travel from Washington to New York for attending a marriage. Can you please help me for booking the flight ticket?

ASSISTANT: Sure, can you please provide your travelling dates?

USER: My departure date is 04/16 and return date is 04/18.

ASSISTANT: May I know your nearest airport codes of travelling please?

USER: My airport codes are from IAD to EWR.

ASSISTANT: Give me a moment please, let me check the flight services on this route.

USER: Ok, make sure my price limit is 200.

ASSISTANT: Katherine Taylor, there are no flights available on this route on your provided dates.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for contacting us.