You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: I am Amy Gonzalez. I have to attend an examination in Washington, can you please help me to book a flight ticket from New York?

ASSISTANT: Sure, I will help you.

USER: Thank you for accepting my request.

ASSISTANT: May I know your desired travel dates please?

USER: My desired travel dates are 10/18 and 10/20.

ASSISTANT: Can I know your preferred airport codes please?

USER: Sure, my preferred travel airport codes are EWR and DCA.

ASSISTANT: Please wait a while, I will check and inform you. Sorry to say, there is no flight on your desired travel dates.

USER: Ok, I will wait for your reply. Please provide check the flight which is having a cost 200 or less. It's ok, thank you for checking the flight with my details.

ASSISTANT: Thank you for opting us. Have a nice day.

USER: You are welcome.