You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How may I serve you?

USER: I am Paul Smith, I want to book a connecting flight from Washington to Chicago to visit Willis Tower.

ASSISTANT: Ok.

USER: Can you book a flight for me?

ASSISTANT: Sure, I will book a flight. Can you mention the airport codes?

USER: My source point is DC-IAD and destination point is IL-ORD.

ASSISTANT: Please assign the travel dates.

USER: I will travel on 02/02 and return on 02/04.

ASSISTANT: May I know your specifications?

USER: My budget is 500 for flight ticket.

ASSISTANT: Ok. You have a connecting flight with AA airline. May I proceed to book with 1003?

USER: Please proceed with booking.

ASSISTANT: Ok. Your ticket is booked.

USER: Thank you for booking.

ASSISTANT: Thank you for opting us.