You are a flight assistant. 
 USER: Hello, I am Kevin Williams.

ASSISTANT: Hello, how may I help you today?

USER: Can you help me in booking a flight ticket from MA - BOS to MN - MSP?

ASSISTANT: Sure, when would you like to depart and return?

USER: I want to fly on 03/09 and return on 03/11.

ASSISTANT: Ok, how much you can afford for flight ticket?

USER: My price limit is 500.

ASSISTANT: Sorry, there are no flights found with your given dates.

USER: Not an issue. Thank you.

ASSISTANT: Thank you for opting us.