You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you now?

USER: Help me in cancelling my flight reservation. As I modified my travel dates.

ASSISTANT: Sure, I am glad to help you with that.

USER: Thank you.

ASSISTANT: Can I know your name to check your previous reservation?

USER: Christopher Walker here.

ASSISTANT: Please be on hold to check.

USER: Sure.

ASSISTANT: As per your request, I have found your reservation and cancelled it successfully.

USER: Thanks for your service.

ASSISTANT: Thank you for approaching us.