You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you today?

USER: Can you help me to book a direct flight from DTW?

ASSISTANT: Sure, let me know your travel dates?

USER: My travelling dates are May 12 and 14, so please book a flight on my preferred dates.

ASSISTANT: May I know your destination airport code?

USER: I want to return from JFK at evening time.

ASSISTANT: Ok, can I know your name please?

USER: My name is Christine Collins.

ASSISTANT: Sorry, no flights found on your preferred travel dates.

USER: No issues, thank you for your information.

ASSISTANT: Thank you for contacting us.