You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hi. How may I help you?

USER: Can you please help me in booking a flight ticket from DCA to SEA?

ASSISTANT: Can I have your trip dates?

USER: Sure, my travel dates are from May 26 to May 28.

ASSISTANT: Do you have any class preferences?

USER: I prefer business class.

ASSISTANT: Do you have any connection preferences?

USER: I need a connecting flight.

ASSISTANT: May I know your name please?

USER: Linda Green here.

ASSISTANT: Is there any other preferences?

USER: No.

ASSISTANT: No flights found as per your preferences. Thank you.

USER: Ok, no problem. Thank you for the information.