You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you for the day?

USER: I am Lisa Adams. I am planning to change an existing reservation, due to health issue. Can you please change my reservation?

ASSISTANT: Sure, please hold for a moment, let me check the previous reservation.

USER: Sure, I will wait.

ASSISTANT: Sorry to tell you, there is no reservation found with your name in our reservation list.

USER: Not an issue, anyhow thank you so much for your help.

ASSISTANT:  Lisa Adams, thank you approaching us.