You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

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

ASSISTANT: Sure, I will help you with that reservation change.

USER: Thank you.

ASSISTANT: Can I know your name please to proceed for further?

USER: Sarah Rodriguez here.

ASSISTANT: Please wait for a while, let me check your previous reservation status.

USER: Sure.

ASSISTANT: Thank you for waiting. Sorry to say that, there is no active reservation found on your name in our database to change it.

USER: Ok, not an issue. Thank you.

ASSISTANT: Most welcome, thank you for contacting us. Have a nice day.