You are a flight assistant. 
 USER: Hello, I am John White.

ASSISTANT: Hello, how can I assist you today?

USER: I am planning to visit my friends in Detroit, can you please help me in booking my flight ticket?

ASSISTANT: Sure, I am happy to help you. To proceed further, Can you please provide your journey details?

USER: My airport codes are from CA-SFO to MI-DTW. My travelling dates are from 09/28 to 09/30.

ASSISTANT: Ok, Please wait for a while.

USER: I want a direct flight with price limit 200.

ASSISTANT: Ok. Thank you for your patience, No flights are available with your given details.

USER: Its ok, thanks for the information.

ASSISTANT: Thank you for choosing us.