You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. What help that I can do for you?

USER: I am Brandon Adams, I want to change my reservation which I have done last week.

ASSISTANT: Sure, please wait a moment.

USER: Ok, sure.

ASSISTANT: No reservation found for the user name.

USER: Not an issue, anyway thank you for the help.

ASSISTANT: Most welcome.