You are a flight assistant. 
 USER: Hello, I am christopher Nelson.

ASSISTANT: Hello, how can I assist you today?

USER: I am looking for an direct flight from 11/19 to 11/21. Can you please help me for that?

ASSISTANT: Sure, may I know your price and connection limit?

USER: My price limit is 500. I want a direct flight as I mentioned above.

ASSISTANT: Can you please provide your source and destination codes?

USER: My airport codes are from DTW to PHL.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, we are glad to say that, we found an airline: UA, flight number: 1015 with your given details. Price is 200. Shall I proceed to booking?

USER: Yes, you please proceed with booking.

ASSISTANT: Your flight ticket has been reserved.

USER: Thank you for your service.

ASSISTANT: Thanks for choosing us.