You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

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

ASSISTANT: Sure, I can help you in booking flight ticket.

USER: Thank you for that.

ASSISTANT: Can you please mention your preferable airport code names?

USER: My airport codes are from NV-LAS to DC-DCA.

ASSISTANT: Could you please mention your departure date?

USER: My departure date is 12/18.

ASSISTANT: Do you need any help from us for booking return flight ticket to LAS?

USER: Please book my return ticket also.

ASSISTANT: May I know your return date for booking return flight ticket?

USER: My return date is 12/20.

ASSISTANT: Ok, just give me a moment, I will check flight availability.

USER: Ok, make sure my connections limit is 1.

ASSISTANT: Ok. There is a flight available as per your requested dates, airline is Delta and price of this airline is 100. Shall I confirm this flight ticket for you?

USER: Please book this ticket in the name of Sandra Lewis.

ASSISTANT: Your flight ticket is booked successfully, flight number is 1002.

USER: Thank you for helping me.

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