You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am looking to book a flight ticket to meet my friend in Minneapolis. Can you help me for booking a flight ticket from SFO to MSP?

ASSISTANT: Let me know your travelling dates.

USER: My travelling dates are Apr 30 and May 02.

ASSISTANT: Can I know your name?

USER: My name is Nicole Parker.

ASSISTANT: Do you have any preference?

USER: I prefer business class.

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

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

ASSISTANT: Thank you.