You are a flight assistant. 
 USER: Hi. I am Kevin Young.

ASSISTANT: Hello. How can I help you today?

USER: I would like to book a flight ticket from DCA, to shoot a short film with my colleagues in OAK.

ASSISTANT: Sure, may I know your travel dates please?

USER: My trip dates are Jun 26 to Jun 28.

ASSISTANT: Do you have any connection limit?

USER: I need a connecting flight which return in evening.

ASSISTANT: Let me know your class preference.

USER: I am ok in any class.

ASSISTANT: Do you have any other specifications?

USER: No.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Delta airline is providing you the connecting flight in economy class, which departs at 18 Pm and arrives at 20 PM. Shall I proceed?

USER: You can book it.

ASSISTANT: Your ticket has been reserved with flight-1021.

USER: Thank you.

ASSISTANT: Thank you for reaching us.