You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: As it is a valentine week, we are planning to go for trips, just to cherish our memories. So, kindly book a flight on 02/12.

ASSISTANT: Sure, Please can I have your country airport codes?

USER: I am planning to start from BOS. And my destination is SFO.

ASSISTANT: Please share me your return date.

USER: I am going to return on 02/14. Check flights with in a limit of 500.

ASSISTANT: Sorry for the inconvenience, there are no flights found with your requirement. Please may I know your name?

USER: Ok. I am Jonathan Davis.

ASSISTANT: Have a good day.

USER: Thank you for sharing information.