You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to attend a Seminar in Washington. Can you please help me for booking the flight ticket?

ASSISTANT: May I know your trip dates?

USER: My travelling dates are July 10 and July 12.

ASSISTANT: Do you have any connecting flight preferences?

USER: I prefer single connecting flight.

ASSISTANT: Is there any other concern?

USER: No.

ASSISTANT: May I know your nearest airport codes please?

USER: My airport codes are MSP and IAD.

ASSISTANT: May I know your name please?

USER: My name is Cynthia Scott.

ASSISTANT: No flights found as per your preferences.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for choosing us.