You are a flight assistant. 
 USER: Hi. Katherine Perez here.

ASSISTANT: Hello, how can I help you today?

USER: Can you change my flight ticket reservation?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry to say that, no reservation was found with your good name.

USER: Ok, that is not a problem. Thank you.

ASSISTANT: Thank you for reaching us.