You are a flight assistant. 
 USER: Hi. Kimberly Wilson here.

ASSISTANT: Hello, how may I support you at present?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, we are here to help you to change it.

USER: Thank you.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to inform you that, there was no reservation found on your specified name to change it.

USER: Not a problem, thank you.

ASSISTANT: Thank you for approaching us.