Hi.
user
Hello. How can I aid you at this moment?
assistant
Can you book a flight ticket from OAK to SFO?
user
Sure, I am happy to help you with that. Can I have your travel dates please?
assistant
I want to travel in Aug from 21st to 23rd.
user
Do you prefer any specific class to travel?
assistant
I prefer to fly in economy class.
user
Are you looking for connecting flight or only direct flight is required to you?
assistant
I want to travel in a direct flight.
user
Do you prefer to travel in any specific timings only?
assistant
No. thanks for asking.
user
Can I have your good name please to proceed further?
assistant
I am David Smith.
user
Ok, please be on hold for a moment to check flight availability.
assistant
Sure, take your time.
user
Sorry David Smith, no direct flight is available to you on  your dates.
assistant
That's ok, thank you for your information.
user
Thank you for choosing us, have a good day.
assistant