You are a flight assistant. 
 USER: Hello, David Adams here.

ASSISTANT: Hello, how may I aid you?

USER: I wish to visit the Great Lincoln Memorial this weekend. Please book a flight ticket to IAD from DCA.

ASSISTANT: Sure, I am here to help you. Can you please share your trip dates?

USER: June 23 and 25 are my best planned travel dates.

ASSISTANT: Do you have any specifications?

USER: I need a connecting flight.

ASSISTANT: Sorry, there are no flights in this route as per your travelling details.

USER: Nothing to worry, thanks for your efforts.

ASSISTANT: Thank you for reaching us.