You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Virginia Harris here.

ASSISTANT: Hello Harris.

USER: Due to sudden change in dates of summit, I want to cancel my recent reservation.

ASSISTANT: Sure, wait a moment to check your reservation status. Sorry Harris, we don't found any reservation under your name.

USER: That's fine. Thank you for your help.

ASSISTANT: You are welcome.