You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Sandra Moore. I want to change an existing reservation, due to my interview got postponed.

ASSISTANT: Ok Sandra, please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting. Sorry, no reservation found with your name.

USER: Not an issue.

ASSISTANT: Ok, thanks for choosing us.

USER: Thanks for your quick response.