You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I want to cancel my recent reservation due to sudden change in my trip.

ASSISTANT: Yes, I am here to assist you. Can you please let me know your name to check the existing reservation?

USER: Sure, my name is Carol Turner.

ASSISTANT: Sorry , I have checked our database but I can not find any reservation under your name.

USER: No problem, thank you for your help.

ASSISTANT: My pleasure, thank you for choosing our service.