You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: David Perez here. I would like to meet my childhood friend at Washington, please help me in booking a ticket from JFK to DCA.

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

USER: My planned travel dates are on Dec 16 and Dec 18.

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

USER: I would like to depart and return in the afternoon only.

ASSISTANT: Would you like to prefer direct flight or connecting flight?

USER: I prefer a connecting flight.

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

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for reaching us.