You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: My name is Dennis Turner, please help me to book a direct flight to reach Washington.

ASSISTANT: Sure, can I know your travelling dates?

USER: I will fly on 15th June and return on 17th June.

ASSISTANT: From which airport are you going to board and land?

USER: My source airport is DFW and destination is DCA.

ASSISTANT: Do you need a connecting flight?

USER: No, I need a direct flight.

ASSISTANT: Wait a minute.

USER: Sure.

ASSISTANT: Sorry, there are no flights available on your request.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for opting us.