You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: Can you aid me to book a flight ticket from IAH to ORD?

ASSISTANT: Please provide your journey dates.

USER: My trip dates are Sep 9 and Sep 11 respectively.

ASSISTANT: Do you need any specifications?

USER: I prefer for business class flight to travel.

ASSISTANT: May I know your name?

USER: Stephanie Carter.

ASSISTANT: There are no flights available on your routes.

USER: Thank you.

ASSISTANT: Thank you for choosing us.