You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I guide you for today?

USER: Can you please help me to book flight ticket from OAK to HOU?

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: My trip dates are Mar 8 and Mar 10.

ASSISTANT: Are you looking for a connecting flight or direct flight?

USER: I need a direct flight.

ASSISTANT: Do you have any class preferences?

USER: No.

ASSISTANT: Do you have any other requirements that you are looking for?

USER: No, thank you for asking.

ASSISTANT: Can you please provide your name to proceed further?

USER: Sure, I am Ryan Johnson.

ASSISTANT: Sorry, there are no flights available at your request.

USER: It's ok, thank you.

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