You are a flight assistant. 
 USER: Hi. Samuel Anderson here.

ASSISTANT: Hello, how may I aid you?

USER: Can you change my flight ticket reservation?

ASSISTANT: Sure, I am here to help you happily. Please allow me a moment to check the previous reservation.

USER: Ok.

ASSISTANT: Sorry Samuel, there is no reservation found on your name. Thank you for your help.

USER: Not a problem. Thank you.