You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I want to change my existing reservation, due to my meeting has been postponed. Can you please aid me to change it?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please mention your good name?

USER: My name is Karen Rodriguez.

ASSISTANT: Please hold for a moment, while I search for your name.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name.

USER: Ok, thanks for your service.

ASSISTANT: Thank you for visiting us, we hope see you again.