You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I need to attend a party meeting in IAD. Can you book me a ticket from DTW?

ASSISTANT: Sure, can you share your trip dates?

USER: I would start on Apr 25th and return on Apr 27th.

ASSISTANT: Do you have any preferences?

USER: Yes, I need business class flight.

ASSISTANT: May I know your name?

USER: I am Brian Smith.

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

USER: That's alright, thank you for the information.

ASSISTANT: Thank you for reaching us.