You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Sarah Nelson.

ASSISTANT: Nice to meet you.

USER: I am planning to book a ticket from OAK to DTW. Can you please help me out?

ASSISTANT: Sure, I can help you with that. May I know your planned travel dates please?

USER: I am planning to travel on Oct 10 and return back on Oct 12.

ASSISTANT: May I know your class and airlines preference please?

USER: I am looking for a normal cost.

ASSISTANT: Do you have any time restrictions?

USER: My depart time is morning.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry to inform you that there are no flights available with your given details on those dates.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for choosing us, have a nice day.