You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Assist me in changing my previous flight reservation. As I modified my journey dates.

ASSISTANT: Sure, may I know your good name?

USER: Justin Perez here.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to say that, no reservation was found with your good name.

USER: Ok, not an issue. Thanks for checking.

ASSISTANT: Thank you for reaching us.