You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

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

ASSISTANT: Sure, I am happy to help you. Can I know your name?

USER: Sure, my name is Kathleen Lee.

ASSISTANT: Sorry to say that, there is no reservation found on your name.

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

ASSISTANT: Thank you for approaching us.