You are a flight assistant. 
 USER: Hello. I am Andrew Davis.

ASSISTANT: Hello. How can I aid you?

USER: Due to sudden work, I want to change my reservation. Can you please help me with it?

ASSISTANT: Sure, please allow me a moment.

USER: Ok.

ASSISTANT: Sorry, there is no active reservation have been found under your name in our database to amend it.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for reaching us.