You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: I am looking to book a flight ticket from ORD to DCA. Can you help me for that?

ASSISTANT: Sure, I am here to help you. May I know your travel dates please?

USER: My travelling dates are Apr 20 and Apr 22.

ASSISTANT: Ok, do you have any specifications?

USER: My return time is afternoon.

ASSISTANT: I found a flight for you with Delta Airlines and it costs you 100. Shall I proceed?

USER: Ok, proceed for booking.

ASSISTANT: On whose name you would like to book this ticket?

USER: My name is Brenda King.

ASSISTANT: Your ticket has been booked with 1001 flight number.

USER: Thank you for booking.

ASSISTANT: Welcome, thank you for choosing us. Have a safe flight.