You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I be at your service today?

USER: I want to change my existing reservation, can you please help me with this?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: May I know your name to check your reservation status?

USER: I am Laura Evans.

ASSISTANT: Ok, please be on hold.

USER: Sure.

ASSISTANT: Sorry to inform you that, we could not find any reservation with your name in our portal.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.