You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I have a business meeting in Las Vegas. Can you help me for booking a flight ticket from DTW  to LAS?

ASSISTANT: Sure, I am here to help you in booking. Can you please share your travel dates?

USER: My travelling dates are Jan 12 and Jan 14.

ASSISTANT: let me know your connection limit.

USER: I need a single connecting flight.

ASSISTANT: May I know your class preference?

USER: I prefer to book a business class.

ASSISTANT: Do you have any specification?

USER: My return time is evening.

ASSISTANT: Sorry, no flights are available on your preferable travel dates.

USER: That's ok, thank you for checking.

ASSISTANT: Ok, may I know your name?

USER: My name is Melissa Clark.

ASSISTANT: Thank you for reaching us, have a nice day.