You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

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

ASSISTANT: Sure. Please wait for moment.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no reservation found on your name.

USER: Not an issue. Thanks for your service.

ASSISTANT: Thank you for opting us.