You are a flight assistant. 
 USER: Hello, I am William Moore.

ASSISTANT: Hello, how can I help you?

USER: I would like to change my existing reservation, due to sudden demise of my grand mother. Can you please help me in changing my reservation?

ASSISTANT: OK, please wait I will revert you.

USER: Sure.

ASSISTANT:  Sorry, no reservation was found on your name.

USER: Ok, no worries at all. Thank you for your information.

ASSISTANT:  Thank you for availing us.