You are a flight assistant. 
 USER: Hello.

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

USER: I want to book a flight from Chicago to attend a meeting with Client at Washington. Can you book a business class flight for me?

ASSISTANT: Sure, I am happy to help you with that. Can I have your travel dates please?

USER: I will travel on Aug 15 and return on Aug 17.

ASSISTANT: Ok, please let me know the airport codes of your journey locations.

USER: My sourced point is ORD and my destination is IAD.

ASSISTANT: Ok, please let me know the preferable timings of your journey.

USER: I am fine with any timing.

ASSISTANT: Ok, please wait a  moment.

USER: Sure.

ASSISTANT: Sorry to inform you that no flight is available in business class on your dates.

USER: Ok, thank you for the information.

ASSISTANT: Can I have your good name please for documentation purpose?

USER: My name is Carol Harris.

ASSISTANT: Thank you for choosing us, have a good day.