You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: William Brown here. I would like to book a ticket from SEA to DTW, can you please help me with that?

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

USER: The travel dates are from 10/07 to 10/09.

ASSISTANT: Let me check for the availability of flight.

USER: Ok.

ASSISTANT: William, I am sorry to inform you that there is no flight available at your request.

USER: That's ok, thank you for your help.

ASSISTANT: Thank you for contacting us, have a great day.