You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, what can I do for you?

USER: I am David Nelson, can you help me for cancelling my recent reservation?

ASSISTANT: Sure, please wait a minute.

USER: Ok, I will wait for your reply.

ASSISTANT: Thank you for waiting. Unfortunately there is no reservation found by your name.

USER: Oh! It's ok, no problem. Oh! It's ok, no problem. Thank you for your services.

ASSISTANT: Thank you for approaching us and have a nice day.