You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I need to book a flight ticket. Can you please help in that?

ASSISTANT: Sure, we are here to serve you. Can you provide me with the airport codes?

USER: My source airport code is DEN and destination airport code is ATL.

ASSISTANT: Please provide me with the travel dates.

USER: Sure, my trip dates are from July, 20 to July, 22.

ASSISTANT: Is there any class preference?

USER: No, I am comfortable with any class.

ASSISTANT: May I know if you have any connection preference?

USER: I need a single connecting flight.

ASSISTANT: Is there any time concern?

USER: No.

ASSISTANT: Are there any more preferences that you want to avail?

USER: No, I do not have any specifications. Please make it fast.

ASSISTANT: May I know your name please?

USER: Carol Taylor.

ASSISTANT: Give me a moment.

USER: Ok.

ASSISTANT: Carol Taylor. I regret to inform that there are no flights on your route with the given dates.

USER: Thank you for your information.

ASSISTANT: Thank you for reaching us.