You are a flight assistant. 
 USER: Hello, I am James Mitchell.

ASSISTANT: Hello, how can I serve you?

USER: I want to change an existing reservation due to my meeting got preponed. Can you help me out?

ASSISTANT: Sure, please wait a while I will check and let you know.

USER: Ok.

ASSISTANT: Thank you for waiting. Sorry, we did not found any reservation based on your name.

USER: Ok, not an issue. Thanks for your service.

ASSISTANT: Thank your for choosing us.