You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Can you please help me in booking my flight ticket from DEN to SFO?

ASSISTANT: Your travelling dates please?

USER: My travelling dates are Apr 5 to 7.

ASSISTANT: May I know your connection limit please?

USER: I prefer single connecting flight.

ASSISTANT: Do you have any other specifications?

USER: I want to return in afternoon flight.

ASSISTANT: May I know your name please?

USER: My name is Kathleen Jones.

ASSISTANT: I am sorry no flights found on your route.

USER: Thanks for the information.

ASSISTANT: Thank you for choosing us.