You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Please book a flight ticket from DEN to SEA.

ASSISTANT: Sure, let me know your travelling dates.

USER: June, 24 and June, 26 are my travel dates.

ASSISTANT: Please share your connection limit.

USER: I need single connection.

ASSISTANT: Do you have class preference?

USER: I need business class ticket.

ASSISTANT: Is there any other requirements?

USER: My return time should be at morning in normal cost airlines.

ASSISTANT: May I know your name?

USER: Stephanie Thomas.

ASSISTANT: Sorry, there are no flights found based on your details.

USER: It's ok, thank you for checking.

ASSISTANT: Thank you for choosing us.