You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: Could you book my ticket in a direct flight?

ASSISTANT: Sure, please share me your source and destination points.

USER: My genesis and terminus airport codes are DEN and IAD.

ASSISTANT: May I know your planned travel dates?

USER: My itinerary dates are Mar 8 and Mar 10.

ASSISTANT: Is there any class preference for you?

USER: I have no specific requirements.

ASSISTANT: Your good name please.

USER: Jeffrey Johnson here.

ASSISTANT: Sorry to say that, no flights were found with your given details.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.