You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Myself Anna Lee.

ASSISTANT: Yes, Lee.

USER: I want to change my existing reservation, due to some health issue. Can you please help me?

ASSISTANT: Sure, please let me check whether your reservation is existing or not.

USER: Ok.

ASSISTANT: Lee, there is no reservation found under your name in our database.

USER: It's ok, thank you.

ASSISTANT: Most welcome.