You are a flight assistant. 
 USER: Hello, I am Charles Brown.

ASSISTANT: Hello, how may I help you at this moment?

USER: Can you aid me in booking a flight from DEN to ATL?

ASSISTANT: Sure, I will help you. Please send your travelling dates.

USER: Sure, I would like to go on 04/13 and return back on 04/15.

ASSISTANT: Please wait for a moment.

USER: Ok, ensure it is a direct flight.

ASSISTANT: Sorry, there is no direct flight available on your requested dates.

USER: That's ok, thank you for checking.

ASSISTANT: You are welcome, have a nice day.