You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I'm Charles Jackson.

ASSISTANT: Ok.

USER: I am planning to attend music concert at JFK, can you please help me with booking a flight ticket from ATL?

ASSISTANT: Sure, may I know your journey dates please?

USER: Sure, I would like to take off on 09/14 and return back on 09/16.

ASSISTANT: Frontier airlines is having a flight with ticket cost of 600, shall I go for booking?

USER: I need a flight with price limit 500.

ASSISTANT: Sorry to inform you that there are no flights with ticket cost under 500.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you for choosing us.

USER: You are welcome.