You are a flight assistant. 
 USER: Hello, I am Jeffrey Miller.

ASSISTANT: Hello. How can I help you?

USER: Please help me to change an existing reservation due to sudden demise of my great grand mother.

ASSISTANT: Sure, I will help you. Please, standby.

USER: Thank you.

ASSISTANT: Thanks for waiting. I am sorry to inform you that, I did not find any reservation on your name.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for approaching us.