You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Catherine Carter here. I want to travel from DCA to OAK for attending a seminar. Can you please help me for booking the flight ticket?

ASSISTANT: May I know your travelling dates?

USER: My travelling dates are from 10/28 to 10/30.

ASSISTANT: Sorry, no flight found.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for raechging us.