You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you for today?

USER: I am planning to book a ticket from SFO to ATL. Can you please help me out?

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: I am planning to travel on Dec 21 and return back on Dec 23.

ASSISTANT: Are you looking for a connecting flight or direct flight?

USER: I am looking for a connecting flight.

ASSISTANT: Do you have any class preferences?

USER: No, my return time should be morning.

ASSISTANT: Do you have any other requirements that you are looking for?

USER: No.

ASSISTANT: Can you please provide your name to proceed further?

USER: My name is Debra Martin.

ASSISTANT: Sorry, there are no flights available at your request.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for contacting us, have a nice day.