You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I want to book a flight ticket from DTW to HOU. Could you help me in booking?

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

USER: My travelling dates are from Dec 18 - 20.

ASSISTANT: Do you have any connection limit?

USER: Yes, I prefer for connecting flight.

ASSISTANT: May I know your airline preference?

USER: I am comfort with any.

ASSISTANT: Do you have class preference?

USER: No.

ASSISTANT: May I know your name please?

USER: Daniel Hill here.

ASSISTANT: Sorry, there are no flights in this route as per your travelling details.

USER: That's ok, thank you.