You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Thomas Carter. I need to change my existing reservation, Can you help me for change my reservation please?

ASSISTANT: Sure, please wait for a moment, I will check the existing reservation on your name.

USER: Sure.

ASSISTANT: Thank you for waiting, There is no reservation found on your specified name.

USER: Ok, no issues. Thanks for your information.

ASSISTANT: Thank you for approaching us.