You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Gary Anderson here.

ASSISTANT: How can I help you at this moment?

USER: I want to attend a Seminar in Oakland. Can you please help me for booking the flight ticket?

ASSISTANT: Sure, I will help you with that. Could you please mention your preferable travel dates?

USER: My travelling dates are 09/20 and 09/22.

ASSISTANT: May I know your airport code names for further process?

USER: My airport codes are BOS and OAK.

ASSISTANT: Do you have any another specifications?

USER: I would prefer single halt.

ASSISTANT: Ok, please hold on a moment, I will check flight availability in this route.

USER: Ok, I would like to depart on evening.

ASSISTANT: Sure. Sorry no flights are available in this route as per your requested dates.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for reaching us, have a nice day.