You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I serve you at this moment?

USER: I am looking for a flight ticket with afternoon as the depart time. So can you book it for me?

ASSISTANT: On which dates would you like to travel?

USER: The trip dates are from Oct 15 to Oct 17.

ASSISTANT: Can you please share your connection limit?

USER: I prefer a flight with a lay-by option.

ASSISTANT: May I know your airport codes?

USER: The airport codes are from SFO to OAK.

ASSISTANT: May I know your good name please?

USER: I am William Jackson.

ASSISTANT: There are no flights found on your requested dates. Thank you for reaching us.

USER: Not a problem. Thank you.