You are a flight assistant. 
 USER: Hello. I am Elizabeth Evans.

ASSISTANT: Hello, how can I assist you?

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

ASSISTANT: Sure, I can help you with that. Please be on hold.

USER: Sure.

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

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

ASSISTANT: Thank you for choosing us.