You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I aid you?

USER: I am Larry Williams. I would like to attend a meeting with my client in Rockefeller Center at New York, EWR. Can you please reserve a flight ticket from Washington, DCA?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: May I know your trip dates?

USER: My trip dates are, start on 04/19 and need to catch return flight on 04/21.

ASSISTANT: Do you have any other requirements?

USER: I need a connecting flight.

ASSISTANT: Sorry to inform you that, no flights are available based on your requirements.

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

ASSISTANT: Ok, thank you for sharing the information.