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

ASSISTANT: Hello, do you need any help from us?

USER: Can you change my flight ticket reservation?

ASSISTANT: Sure, please allow me a moment.

USER: Ok.

ASSISTANT: Sorry, there is no reservation with your name in our portal to make changes.

USER: Not a problem. Thank you.

ASSISTANT: You are welcome, have a great day.