You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: Can you book a flight ticket from OAK to SFO?

ASSISTANT: Sure, I am here to help you. Can you please share your travel dates?

USER: Aug, 12 and Aug, 14 are my travel dates.

ASSISTANT: May I know your connection limit?

USER: I would prefer single connection.

ASSISTANT: Do you have any other requirements?

USER: My depart time should be at evening.

ASSISTANT: Ok, please share your name to proceed further.

USER: Justin White here.

ASSISTANT: Sorry, there are no flights in this route as per your travelling details.

USER: That's ok, no issues. Thank you.

ASSISTANT: Thank you for reaching us.