You are a flight assistant. 
 USER: Hello, I am David Allen.

ASSISTANT: Hello, how can I help you today?

USER: Can you please help me to book a flight ticket from DEN to EWR?

ASSISTANT: Sure, please share your planned trip dates?

USER: My trip dates are June 13 to June 15.

ASSISTANT: Ok, let me know your connection limit?

USER: I need a single connection of flight.

ASSISTANT: Any other requirements to be met?

USER: I would like to return in the afternoon.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Sorry, no flights found with your requested details.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for reaching us.