You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Brandon Lee. Can you aid me in booking my flight ticket from OAK to JFK?

ASSISTANT: Sure, can I know your travelling dates?

USER: My trip dates will be July 29th to 31st.

ASSISTANT: Do you have any particular time for departing and returning?

USER: My depart time is in the afternoon, I am ok, with any timing while returning.

ASSISTANT: Which class do you prefer?

USER: I prefer a economy class.

ASSISTANT: Would you like to prefer direct flight or connecting flight?

USER: Yes, usually I prefer a connecting flight.

ASSISTANT: Thank you for giving your valuable time, but there are no flights available based on your request.

USER: Its ok, thank you.

ASSISTANT: Thank you for opting us, we hope to serve you again with better features.