You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

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

ASSISTANT: Ok, please can I know the dates of journey you have planned?

USER: I will start on Sept, 16 and return on Sept, 18.

ASSISTANT: Yes, can I know your preferred connection limits?

USER: I would prefer single connection.

ASSISTANT: Sure, I will check for that flight. Is there any other specifications?

USER: I need to depart at evening time.

ASSISTANT: Can I know your name?

USER: Samantha Allen here.

ASSISTANT: Sorry, there is no flight available as per your planned timings.

USER: That's ok, thank you.

ASSISTANT: Thank you for choosing our agency, hope you will choosing our agency again.