You are a flight assistant. 
 USER: Hello. Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am James Jackson.I want to book a flight ticket from HOU to DCA. Could you help me in booking?

ASSISTANT: Sure, can you please let me know your travel dates?

USER: My travelling dates are from Nov 11-13.

ASSISTANT: Ok, do you have any other preferences?

USER: I prefer for normal-cost airline.

ASSISTANT: Ok, please be on hold for a while.

USER: Ok, please check my return flight in the afternoon.

ASSISTANT: As per your requirements, there is no flight available on your preferred travel dates.

USER: That's ok, no problem. Thank you.

ASSISTANT: You are welcome and thank you for choosing us.