You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: My name is Ronald Lopez. I want to change my departure day in my existing reservation, can you please help me out?

ASSISTANT: Sure, please wait for a moment.

USER: Sure, take your time.

ASSISTANT: Sorry, there is no reservation found on your name in our database to change.

USER: That's ok, thank you for the information.

ASSISTANT: You are welcome.