You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Can you help me in booking the flight ticket from DCA to JFK?

ASSISTANT: Sure, can I know your trip dates?

USER: Sure, my planned travel dates are Mar 28 and Mar 30.

ASSISTANT: Do you need a connection limit?

USER: Yes, please look for a connecting flight.

ASSISTANT: Do you have any class preference?

USER: No, I don't have any other specifications.

ASSISTANT: May I know your name, please?

USER: Myself Donna Martinez.

ASSISTANT: Sorry, no flights available on your travelling dates.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you for choosing us.