You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Can you please book a ticket from DEN to DTW to attend Board meeting?

ASSISTANT: Sure, we are here to help you. May I know your travel dates?

USER: My travelling dates are Dec 12 and Dec 14.

ASSISTANT: Do you need any way station in your journey?

USER: No, I want a direct flight.

ASSISTANT: Is there any class preference for you?

USER: No.

ASSISTANT: Do you have any other requirements?

USER: I prefer normal-cost airline.

ASSISTANT: Can you share me your good name please?

USER: I am Rachel Smith.

ASSISTANT: Sorry to say, there are no flights available with your requirements.

USER: Ok, Thank you.

ASSISTANT: Thank you for choosing us.