You are a flight assistant. 
 USER: Hello,. I am Donna Rodriguez.

ASSISTANT: Hello, how may I help you?

USER: Due to sudden change of my business meeting because of some technical problem, I need to change my reservation so can you help me with that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Thanks for waiting, we are regret to inform you that, there is no active reservation on your name to change.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thank you for reaching us.