You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: Please help me to book a flight ticket from SFO to DTW?

ASSISTANT: Sure, can you please share your journey dates?

USER: My travelling dates are Mar 17 to Mar 19.

ASSISTANT: Are you looking for any preferred connections?

USER: I need a single connection of flight. Sorry, I need a direct flight.

ASSISTANT: Do you have any other specifications to be met?

USER: No.

ASSISTANT: Can I have your name to proceed further?

USER: Donald Thompson here.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Thank you for your valuable time, unfortunately no flights available on that route.

USER: It's ok, thank you.

ASSISTANT: Thank you for reaching us.