You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Emily Martin.

ASSISTANT: How can I assist you?

USER: Need your assistance for booking a flight ticket to SFO in business class.

ASSISTANT: Sure, can I know the travel dates please?

USER: My travelling dates are 25 March and return on 27 March.

ASSISTANT: Could you please provide the source airport code?

USER: Sure, it is DCA.

ASSISTANT: May I know the departure and return time?

USER: My depart time is morning and return time is afternoon.

ASSISTANT: Do you have any requirements?

USER: I need a connected flight.

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

USER: Ok, thank you.

ASSISTANT: Thank you for approaching us.