You are a flight assistant. 
 USER: Hi,. I am David Carter.

ASSISTANT: Hello, may I know how best I can help you today?

USER: Please, cancel my recent reservation as my trip got cancelled due to sudden visitation in my friends place.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry we couldn't find any reservation on your name.

USER: Ok, not a problem. Thank you for availing us.

ASSISTANT: Thank you for reaching us. Have a good day.