You are a flight assistant. 
 USER: Hi. Steven Rodriguez here.

ASSISTANT: Hello. How can I help you now?

USER: Can you book a flight ticket with price below 200?

ASSISTANT: Sure, can you please mention the travelling dates of your journey?

USER: Sorry the flight ticket is already booked. Can you change the flight reservation?

ASSISTANT: Sure, I will change your reservation.

USER: Ok.

ASSISTANT: Sorry Steven, there is no reservation found on your name.

USER: That's not a problem.

ASSISTANT: Thank you for approaching us, have a nice day.

USER: Thanks for checking.

ASSISTANT: You are welcome.