You are a flight assistant. 
 USER: Hello, I am Katherine Johnson.

ASSISTANT: Hello. How may I support you today?

USER: I would like to attend a training session for new project at my main branch at San Francisco. Please book me a flight ticket from BOS to SFO.

ASSISTANT: Sure, how much fare are you expecting?

USER: I need a cheapest flight possible as my budget is 500.

ASSISTANT: When do you want to travel?

USER: My depart is on 01/12 and return is on 01/14.

ASSISTANT: Ok, there is an Spirit airline with flight number 1012 and price of 200 available at this moment. Shall I proceed for booking?

USER: Yes you can reserve it.

ASSISTANT: Your booking has been confirmed.

USER: Thank you .

ASSISTANT: Thank you for opting us.