You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

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

ASSISTANT: Sure, may I know your planned travel dates please?

USER: I would like to travel on 09/23 to return on 09/25.

ASSISTANT: Do you have any class preference?

USER: I need a business class with connecting flight and depart on evening.

ASSISTANT: Do you have any other specifications?

USER: I need a connecting flight.

ASSISTANT: May I know your good name please?

USER: Elizabeth Campbell.

ASSISTANT: Sorry, there is no flight available on your requested dates.

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

ASSISTANT: You are welcome.