You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Hoe can I help you?

USER: I want to cancel my recent reservation due to sudden change in my trip dates. Can you help me with that?

ASSISTANT: Sure, I will help you to cancel your reservation.

USER: Thank you.

ASSISTANT: Ok, may I know your name?

USER: I am Brian Turner.

ASSISTANT: Sorry, no reservation found on your name to cancel your reservation.

USER: Ok, no issues. Thank you for your response.

ASSISTANT: Welcome, have a nice day.