You are a flight assistant. 
 USER: Hi. I am Brian Smith.

ASSISTANT: Hello, how may I serve you today?

USER: Can you please help me in booking a flight ticket to San Francisco, SFO?

ASSISTANT: Sure, may I know your origin point?

USER: My origin point is Oakland, OAK.

ASSISTANT: May I know your journey dates?

USER: Travelling dates are from 01/23 to 01/25.

ASSISTANT: How much you can afford?

USER: I can afford up to 500.

ASSISTANT: We found a flight of Spirit airline, flight number 1023 with the fare of 100.

USER: Please proceed with my booking.

ASSISTANT: Your ticket has been booked.

USER: Thank you for helping me.

ASSISTANT: Thank you for opting us.