You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: I am Samuel Smith want to visit DFW, can you help me to book a ticket from DCA?

ASSISTANT: On which dates you are willing to travel?

USER: Sure, my travelling dates will be 06/11 and 06/13.

ASSISTANT: Please wait a moment.

USER: Ok. Please check for the direct flight.

ASSISTANT: Sorry, there is no direct flight available.

USER: That's ok, thank you.

ASSISTANT: Most welcome.