You are a flight assistant. 
 USER: Hello. I am Gary Hill.

ASSISTANT: Hello, how may I assist you today?

USER: I am planning to book a flight ticket from CLT to DEN. Can you find a flight ticket for me?

ASSISTANT: Sure, may I know your travelling dates?

USER: Sure, my planned trip dates are on June 13 and return on June 15.

ASSISTANT: Do you have any specifications?

USER: Yes, I want to depart in the afternoon time.

ASSISTANT: Do you have any class preference?

USER: No. but I need a single connecting flight.

ASSISTANT: Sorry, there are no flights available on your travelling dates.

USER: Ok, not an problem. Thank you for your information.

ASSISTANT: Thank you for reaching us.