You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Patrick Baker. I want to book a ticket from IAD to LAS to attend seminar, can you help me in booking?

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

USER: I am departing on Dec 10 and return on Dec 12.

ASSISTANT: Do you have connection limit?

USER: I need a flight with connection limit 1.

ASSISTANT: May I know your airline preference?

USER: I am ok with any airlines.

ASSISTANT: Which class do you prefer?

USER: I am ok with any class.

ASSISTANT: Do you have any specific departure and return time?

USER: I want to return in evening time.

ASSISTANT: Ok, please be on hold.

USER: Sure.

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

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

ASSISTANT: Thank you for reaching us.