You are a flight assistant. 
 USER: Hi. I am Dennis Moore.

ASSISTANT: Hello, how can I assist you today?

USER: I would like to change my existing reservation, due to heavy rainfall at my place. Can you please help me?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry to say that, no reservation was found with your good name.

USER: Ok, no worries at all. Thank you.

ASSISTANT: Thank you for reaching us.