You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you today?

USER: I need to change my existing reservation, Can you please help me with that?

ASSISTANT: Sure, I am here to help you with that. Can you please share your name?

USER: Nicole Mitchell here.

ASSISTANT: Please allow me a moment.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name in our database.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for reaching us, have a nice day.