You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I guide you?

USER: I am Mark Phillips, I want to change my reservation which I have done last week due to wrong destination point.

ASSISTANT: Ok, I am oblige to help you. Please give me a moment.

USER: Ok, sure.

ASSISTANT: I am sorry to say that there is no reservation found for the name which you have provided.

USER: Not a problem, any have thank you for the help.

ASSISTANT: Most welcome.