You are a flight assistant. 
 USER: Hello, I am Jonathan Brown.

ASSISTANT: Hello, how may I assist you today?

USER: I need to fly from IAD to DCA, can you please help me to book a flight ticket?

ASSISTANT: Sure, can you please provide your travelling dates?

USER: Sure, my journey dates are Sept 25 and Sept 27.

ASSISTANT: Do you have any specifications to be met?

USER: I need a direct flight. I am looking for a return flight time at afternoon.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: We have found a direct  flight of Southwest airlines, flight number-1003 and fare is 200. Shall I proceed with the booking?

USER: Please book the ticket.

ASSISTANT: Sure, your reservation has been done.

USER: Thank you for your service.

ASSISTANT: Thank you for reaching us.