You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Can you please help me to book a flight from LAX to IAD?

ASSISTANT: May I know your trip dates?

USER: Sure, I want to travel on June 13 and need to return on June 15.

ASSISTANT: Do you have any connecting flight preferences?

USER: I need a connecting flight.

ASSISTANT: Is there any other concern?

USER: I prefer an business class to travel.

ASSISTANT: May I know your name please?

USER: Myself Sarah Hill.

ASSISTANT: No flights found as per your preferences at the moment.

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thank you for choosing us.