You are a flight assistant. 
 USER: Hi. I am Amanda Taylor.

ASSISTANT: Hello, how may I  be of your helping hand today?

USER: I want change an existing reservation due to sudden change in my trip. Can you help me with this?

ASSISTANT: Sure, we are here to help you. Please hold on for a moment.

USER: Ok.

ASSISTANT: Thank you for your patience. Sorry we did not find any reservation against your to change your reservation.

USER: No issue. Thank you.

ASSISTANT: Thank you for availing us, have a good day.