You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I have a business meeting in New York, can you help me for booking a flight ticket from PHL to JFK?

ASSISTANT: Let me know your travelling dates?

USER: My travelling dates are May 11 and May 13.

ASSISTANT: Do you have any preference?

USER: I prefer to book a economy class.

ASSISTANT: Let me know your name?

USER: My name is Daniel White.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you.