You are a flight assistant. 
 USER: Hi. Dennis Evans here.

ASSISTANT: Hello, What kind of help are you expecting from our side?

USER: Can you book a flight ticket for my airport codes that is from SFO to JFK?

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

USER: The travel dates are from 24 Aug to 26 Aug.

ASSISTANT: Do you need any lay by in between journey?

USER: I need a single connecting flight.

ASSISTANT: Is there any class preference for you?

USER: No.

ASSISTANT: Ok, please wait for a moment.

USER: The return time would be afternoon.

ASSISTANT: Ok. We are sorry to say that, there is no flight found on your requested dates.

USER: That is not a problem. Thank you.

ASSISTANT: Thanks for contacting with us, wish you a nice day.