You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

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

ASSISTANT: Sure, may I know your name please?

USER: My name is Jonathan Smith.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Sorry, there is no active reservation found with your name in our records.

USER: That's ok, thank you for the response.

ASSISTANT: Most welcome.