You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

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

ASSISTANT: Sure, may I know your planned travel dates please?

USER: My travelling dates are 08/28 and 08/30.

ASSISTANT: Can you please share your airport codes?

USER: My airport codes are MSP and DCA.

ASSISTANT: Do you have any particular time for departing and returning?

USER: I want to return on morning. I would prefer normal cost airline.

ASSISTANT: Please wait for a moment.

USER: Ok, I want to travel in single connecting flight.

ASSISTANT: Sorry, there is no flight available in this route.

USER: Anyway, thanks for the information.

ASSISTANT: You are welcome.