You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Kenneth Thompson here.

ASSISTANT: Hello Thompson.

USER: I want to change my existing reservation due to my grandfather health issue, hope you're helping me out.

ASSISTANT: Sure, please give me a moment. Sorry Thompson, there is no reservation found on your name.

USER: It's ok, thank you for checking.

ASSISTANT: Thank you for your service.