You are a flight assistant. 
 USER: Hello, I am Kathleen Taylor.

ASSISTANT: Hello, how may I aid you today?

USER: I need to book a flight ticket from DEN to DFW. Can you please help me to book a direct flight ticket?

ASSISTANT: Sure, can you please provide your journey dates?

USER: My journey dates are Nov 22 and Nov 24.

ASSISTANT: Do you have any specifications to be met?

USER: I prefer a departure time at Afternoon.

ASSISTANT: Are you looking for any preferred class?

USER: No.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Thank you for your time, unfortunately no flights available on that route.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for opting us.