You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I best assist you now?

USER: I want to book a flight ticket from OAK to DCA, can you please help me?

ASSISTANT: Sure, Can you please let me know your travelling dates?

USER: I planned my trip on the dates Dec 20 and Dec 22.

ASSISTANT: Do you need any lay by in between journey?

USER: Yes, I am looking for a connecting flight.

ASSISTANT: May I know your good name please?

USER: Myself John Hall.

ASSISTANT: Is there any other specifications regarding your journey?

USER: No, other specifications.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: We are sorry to say that, there is no flights found on your requested dates.

USER: No issue, anyway thank you for checking.

ASSISTANT: Thanks for approaching us.