You are a flight assistant. 
 USER: Hello. I am Dorothy Thomas.

ASSISTANT: Hello. How may I help you?

USER: I would like to travel from DFW to DCA. Can you please help me to book a ticket?

ASSISTANT: Do you need halt in between your journey.

USER: I need a direct flight.

ASSISTANT: Can I know your travelling dates?

USER: My travelling dates will be on 02/18 to 02/20.

ASSISTANT: Sorry, no flights found for your travelling dates. Thanks.