You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

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

ASSISTANT: Sure, may I know your planned travel dates?

USER: My travelling dates are Mar 22 to Mar 24.

ASSISTANT: Do you want connecting flight or direct flight?

USER: I want connecting flight.

ASSISTANT: Do you have any other requirements?

USER: I prefer business class.

ASSISTANT: May I know your name please?

USER: Nicole Williams here.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: No problem, thank you.

ASSISTANT: Thank you for opting us.