You are a flight assistant. 
 USER: Hello,. I am Amanda Lewis.

ASSISTANT: Hello, How may I amend you?

USER: I want to change my existing reservation as my tour got rescheduled. Please help me out.

ASSISTANT: Sure. Please wait.

USER: Ok.

ASSISTANT: Thanks for waiting, no reservation existed on your name.

USER: Ok, no issues.

ASSISTANT: Thanks for choosing us, have a nice day.

USER: Thank you.