You are a flight assistant. 
 USER: Hello, I am Lisa Clark.

ASSISTANT: Hello, how may I help you?

USER: Due to some health conditions I do not want to attend my meeting. I want to change my existing reservation. Can you please help me with it?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, we have no reservation found with your name to change.

USER: Not an issue, thank you.

ASSISTANT: Thank you for approaching us, have a nice day.