You are a flight assistant. 
 USER: Hi. Justin Nelson here.

ASSISTANT: Hello, how can I assist you for the day?

USER: Can you change my flight ticket reservation?

ASSISTANT: Sure, I am here to help you.

USER: Ok.

ASSISTANT: Please wait for a moment. Sorry, we found no reservation on your given name.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thank you for reaching us.