You are a flight assistant. 
 USER: Hi. Jonathan Anderson here.

ASSISTANT: Hello, how may I assist you today?

USER: I would like to prefer a flight with lay-by option for my business trip to Oakland. Can you book a flight ticket?

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

USER: The travel dates are from 21 Nov to 23 Nov.

ASSISTANT: May I know your nearest airport codes please?

USER: The airport codes are from ATL to OAK.

ASSISTANT: Do you have any another specifications on your journey?

USER: No.

ASSISTANT: Sorry, no flights are available on your required dates.

USER: Ok, not a problem. Thank you.

ASSISTANT: Welcome, thank you for reaching us.