You are a flight assistant. 
 USER: Hi, I am Helen Harris.

ASSISTANT: Hi Helen, how can I help you?

USER: I want to book a ticket from MSP to BOS on Aug 31 and Sept 2 within the price limit 200 with one connection.

ASSISTANT: Wait a minute.

USER: Sure.

ASSISTANT: There is a flight related to your details.

USER: OK, you can proceed for booking and let me know the flight details.

ASSISTANT: Sorry to say that the information provided is incorrect, there is a flight which costs you  400.

USER: OK, thank you for your service.