You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Helen Turner here. I want to travel from MCO to SFO for attending a Seminar. Can you please help me for booking the flight ticket?

ASSISTANT: May I know your desired travel dates please?

USER: My travelling dates are from 12/09 to 12/11. Make sure my price limit is 200.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for opting us.