You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you?

USER: I want to book a flight ticket from OAK to SFO, can you help me with that?

ASSISTANT: Sure, can you share your trip dates?

USER: My travel dates are 05/09 and 05/11.

ASSISTANT: Do you have any preferences?

USER: I need a direct flight in business class.

ASSISTANT: May I know your name?

USER: I am Ruth Martinez.

ASSISTANT: Sorry, there is no flight on your given dates.

USER: That's ok. Thank you for your service.

ASSISTANT: Thank you for opting us.