You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you?

USER: I would like to travel to OAK in this week, so can you help me to book a flight from DCA?

ASSISTANT: Sure, I am glad to help you. May I know your planned trip dates?

USER: Sure, my trip dates are Sept 06 and 08.

ASSISTANT: Can I have your name please?

USER: My name is Jeffrey Jackson.

ASSISTANT: Do you have any connection limit preference?

USER: I prefer connecting flight.

ASSISTANT: Do you have any class preference?

USER: I would like to travel in a economy class.

ASSISTANT: Do you have any airline preference?

USER: No.

ASSISTANT: May I know your time concern?

USER: I want to return at evening time.

ASSISTANT: Thank you for providing the details, please wait a moment while I check with the availability of flights.

USER: Sure.

ASSISTANT: Thank you for waiting, Jeffrey Jackson.

USER: Ok.

ASSISTANT: We are sorry to inform you that, there is no flights available on your mentioned dates.

USER: No issues, thank you for your time.

ASSISTANT: Thank you for reaching our agency.