You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Nancy Parker. I want to change my existing reservation due to health issues.

ASSISTANT: Sure. Please wait a while.

USER: Ok.

ASSISTANT: Thanks for your time. We didnt found any reservation by this name.

USER: Not an issue, thanks for your help.

ASSISTANT: Thank you for choosing us.