You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

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

ASSISTANT: Sure, I'm happy to help you with that. Can I know your good name please?

USER: I am Brenda Robinson.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Brenda Robinson, I have searched your reservation details in our database but there is no active reservation found under your name to do changes in that.

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

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