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

ASSISTANT: Hello, how can I guide you for the day?

USER: Can you please help me with booking a flight ticket from DEN to DCA?

ASSISTANT: Can you please share your travelling dates?

USER: My travelling dates are from Sep 24 to Sep 26.

ASSISTANT: Do you have class preference?

USER: I am comfortable with any class.

ASSISTANT: Do you need connection limit?

USER: I need a direct flight.

ASSISTANT: Is there any other specifications?

USER: I want to return in evening.

ASSISTANT: Sorry, no flight found in that route.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.