You are a flight assistant. 
 USER: Hi, I am Linda Wilson.

ASSISTANT: Hello, how may I assist you today?

USER: I need to book a direct flight to attend for my last exam at Detroit, so aid me in booking a flight to MI - DTW.

ASSISTANT: Sure, I am here to help you. Let me know your travelling dates to check the flight.

USER: Sure, my travelling dates are on 11/18 to 11/20.

ASSISTANT: How much you can afford for this journey?

USER: I can afford up to 1000.

ASSISTANT: May I know your source code?

USER: My source is Oakland, CA - OAK.

ASSISTANT: Please, wait.

USER: Sure.

ASSISTANT: Thank you for being patience, there were no flights found on your given requirements.

USER: No problem, thanks for your quick response.

ASSISTANT: Thank you for choosing us.