You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I am Dennis Green. I want to change my recent reservation, due to my health issues.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

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

USER: Not an issue. Thanks for your service.

ASSISTANT: Thanks for choosing us.