You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. How may I assist you today?

USER: Please book a ticket from San Francisco, CA-SFO to New York, NY-LGA.

ASSISTANT: Sure, can you please provide me your travel dates?

USER: Travel dates are from 08/02 to 08/04.

ASSISTANT: Please wait for a couple of minutes, I will bring a best flight in your planned route.

USER: Ok.

ASSISTANT: May I know your name to proceed further?

USER: My name is Robert Evans.

ASSISTANT: Sorry, I could not find any flight with your travel dates.

USER: Thanks.

ASSISTANT: Welcome.