You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I support you today?

USER: Can you please change my existing reservation in the name of William Taylor?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, no reservation found with your name to change.

USER: It's ok, not an issue. Thank you for your information.

ASSISTANT: Thanks for approaching us.