You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I would like to change my existing reservation, please help me out.

ASSISTANT: Sure, let us know your name please, so that I can check for your reservation status.

USER: My name is Jason Harris.

ASSISTANT: Sorry Harris, I have not found any reservation by your name.

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

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