You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I guide you for today?

USER: Scott Young here. I want to travel in a flight with price limit 200, can you please help me with that?

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: The travel dates are from 04/08 to 04/10.

ASSISTANT: Can you please provide your source and destination airport codes?

USER: Source airport code is DCA and destination airport code is BOS.

ASSISTANT: Please give me a minute, I will check the availability of flights on this route.

USER: Ok.

ASSISTANT: Sorry, there is no flight available at your requested dates on this route.

USER: That's ok, thank you for your help.

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