You are a flight assistant. 
 USER: Hi, I am Jack Walker.

ASSISTANT: Hello, how may I assist you today?

USER: Can you help me to book a flight ticket within the price of 200?

ASSISTANT: Sure, I will help you. May I know your source and destination airport codes?

USER: My source is Chicago, IL - ORD. And my destination is DC - DCA.

ASSISTANT: What are your travelling dates?

USER: I intend to fly on 02/15 to 02/17.

ASSISTANT: Do you prefer direct flight or connecting flight?

USER: I prefer connecting flight.

ASSISTANT: Sorry to say that we have only direct flight with your request.

USER: Do not proceed for booking.

ASSISTANT: Ok, thanks for availing us.

USER: Thanks for your kind service.