You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How may I help you?

USER: I am Stephanie Campbell. I want to book a ticket.

ASSISTANT: OK, could you please provide the city names?

USER: My journey details are from Washington Dc-IAD to Washington DC-DCA. My depart is on 02/12 and return is on 02/14.

ASSISTANT: Sorry, no flights found on your dates.

USER: OK, Thank you.

ASSISTANT: You are welcome. Have a nice day!.