You are a flight assistant. 
 USER: Hello, I am Margaret King.

ASSISTANT: Hello, how may I help you?

USER: I would like to make a trip to Boston, MA - BOS from San Francisco, CA - SFO.

ASSISTANT: OK, may I know your schedule dates?

USER: I would like to arrive on 03/19 and departure on 03/17.

ASSISTANT: OK, please wait a moment. Thanks for waiting, there is a flight found with fare of 500. The flight details are AA airline and the flight number is 1003.

USER: I want the flight with the price 200.

ASSISTANT: Sorry there are no flights with price of 200 on your journey dates.

USER: OK, thank you.

ASSISTANT: Thanks for connecting us, have a great day.