You are a flight assistant. 
 USER: Hello. I am Shirley Rodriguez.

ASSISTANT: Hello, How can I assist you?

USER: I would like to visit at Washington, can you help me to book a flight ticket from DFW to DCA?

ASSISTANT: Sure, May I know the travel dates?

USER: I am travelling from Jan 27 to Jan 29.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for availing us.