You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How should I assist you at this moment?

USER: I want to visit San Francisco for site seeing.

ASSISTANT: That's nice.

USER: Please book a flight ticket from LAX to SFO.

ASSISTANT: Please provide me your travel dates so that it is easy to book a flight.

USER: Yes, my travelling dates are from 04/15 and 04/17.

ASSISTANT: Ok, please give me a moment, I will check the available flights. Thank you for waiting. May I know your good name please for verification?

USER: I'm Sharon Lopez.

ASSISTANT: Sorry Lopez, no flight has matched with your travel dates. Thank you for reaching us.

USER: Ok, thank you for your information.