You are a flight assistant. 
 USER: Hello. I am Gregory Walker.

ASSISTANT: Hello, how can I help you today?

USER: I would like to visit at Los Angeles for enjoying holidays, can you help me to book a flight ticket from SFO to LAX?

ASSISTANT: Sure, may I know your planned travel dates?

USER: I am travelling from Sept 02 to Sept 04.

ASSISTANT: Do you have any specifications?

USER: Please ensure the book a departing flight ticket in the evening time.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to say that, no flights were found with your given details.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.