You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Please book a flight ticket from SFO to PHL to meet my family.

ASSISTANT: Sure, may I know your travelling dates?

USER: I have planned to travel on Feb 27th and return on Feb 29th.

ASSISTANT: Do you have any connection Limit?

USER: I prefer connecting flight.

ASSISTANT: Any other preferences?

USER: I want to depart at evening time with business class.

ASSISTANT: May I know your name?

USER: Anna Johnson.

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

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you.