You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I have to attend for a seminar in OAK. Can you please make a reservation from IAD?

ASSISTANT: Sure, let me know your travel dates please?

USER: I want to travel on Oct 25 and need to return on Oct 27.

ASSISTANT: May I know your connection limit?

USER: I am looking for a flight with single connection.

ASSISTANT: Do you need any other preference?

USER: I prefer an business class to travel.

ASSISTANT: Can I know your name please?

USER: Kimberly Collins here.

ASSISTANT: Sorry, there is no flight available for your request.

USER: Ok, not an issue. Thank you for the information.

ASSISTANT: Thanks for contacting us.