You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: I am Brain Taylor. I need to book a flight ticket from IAD to ATL, Can you please help me for booking?

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

USER: I would like to travel on 09/08 to return on 09/10.

ASSISTANT: Do you have any class preference?

USER: I am comfortable with any class.

ASSISTANT: May I know your connection limit?

USER: I need a connecting flight.

ASSISTANT: Do you have any other specification that you are looking for?

USER: I would be depart on evening and return on morning.

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

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

ASSISTANT: Thank you for contacting us.