You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you at this moment?

USER: I need to book a flight ticket from OAK to DTW, Can you please help me for booking?

ASSISTANT: Sure, I am here to help you with this. Can you please provide your journey dates?

USER: I would like to travel on 01/18 to return on 01/20.

ASSISTANT: Do you have any connection limit preference?

USER: I need a connecting flight.

ASSISTANT: May I know your airline preference for this trip?

USER: I would be return on evening.

ASSISTANT: Do you have any other specifications for this trip?

USER: No.

ASSISTANT: May I know your good name please?

USER: Andrew Perez here.

ASSISTANT: Andrew Perez, there are no flight services are available on this route with your preferences.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for contacting us.