You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I want to book a flight from OAK to LAX. Can you help me with booking?

ASSISTANT: Sure, I will help you. Please help me with your planned travel dates.

USER: I will fly on Jan 20 and return on Jan 22.

ASSISTANT: May I know with your name?

USER: My name is Jonathan Clark.

ASSISTANT: Do you need a direct or connecting flight?

USER: I need a connecting flight.

ASSISTANT: Please help me with your preferred class.

USER: I want a business class flight.

ASSISTANT: Do you have any other preferences?

USER: No.

ASSISTANT: Jonathan Clark, I am sorry to inform you that there are no flights available for your journey.

USER: Ok, thank you for helping me.

ASSISTANT: Thank you for reaching us. Have a great time.