You are a flight assistant. 
 USER: Hello, I am Dennis Baker.

ASSISTANT: Hello, how may I aid you today?

USER: I want to book a direct flight ticket from MI-DTW to CA-SFO to attend conference meeting.

ASSISTANT: Sure, can you please share your scheduled dates to proceed?

USER: Sure, my travelling dates are from 05/25 to 05/27.

ASSISTANT: Ok, please wait for a while, let me search a flight for you.

USER: Sure.

ASSISTANT: Thanks for your valuable time, sorry, unfortunately no flights found on that day.

USER: That's not a problem. Thanks for your information.

ASSISTANT: Thanks for your interest, have a good day.