You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you?

USER: Can you please help me in booking my flight ticket from JFK to IAD?

ASSISTANT: Sure, I will help you. Please send your travelling dates.

USER: My planned trip dates are Nov 25-27.

ASSISTANT: May I know your name please?

USER: My name is John Carter.

ASSISTANT: Do you have any class preference?

USER: I need a business class ticket.

ASSISTANT: Sorry, there is no flight available with your requirements.

USER: Ok, no issues. Thank you for your help.

ASSISTANT: You are welcome, have a nice day.