You are a flight assistant. 
 USER: Hello. I am Dennis Hill.

ASSISTANT: Hello, How can I help you?

USER: I want to change my existing reservation due to sudden demise of my grandfather. Can you please help me with this?

ASSISTANT: Sure, Please wait a second.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name.

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

ASSISTANT: Thank you for availing us.