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

ASSISTANT: Hello, how may I assist you for today?

USER: Can you help me in booking my flight ticket with the fare of 500?

ASSISTANT: Sure, we are here to help you in your booking.

USER: Thank you.

ASSISTANT: May I know your journey dates?

USER: I will start on 01/29 and return on 01/31.

ASSISTANT: Kindly, mention your budget for this journey.

USER: Already mentioned above.

ASSISTANT: Ok. Can you share your airport codes?

USER: My source airport is Chicago, ORD.

ASSISTANT: Thank you for providing your journey details, please wait a while.

USER: My destination airport code is Detroit, DTW. Sure.

ASSISTANT: Thank you for your patience. No flight found on your journey locations.

USER: Ok, not a problem.

ASSISTANT: Thank you for choosing us, have a great day.

USER: Thank you for kind service.