You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Can you aid me in booking a flight ticket from DTW to IAD?

ASSISTANT: May I know your desired travel dates please?

USER: Sure, I would like to go on Apr 17th and return back on Apr 19th.

ASSISTANT: Do you have any specifications?

USER: Make sure it is a single connecting flight.

ASSISTANT: May I know your name please?

USER: Myself Donna Young.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: That's ok, thank you for checking the availability.

ASSISTANT: Thank you for opting us.