You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I want to change my existing reservation due to heavy floods at Denver, can you please help me in this?

ASSISTANT: May I know your name?

USER: Sure, my name is Margaret Hall.

ASSISTANT: Ok, please wait. Sorry, no reservation found your name to change.

USER: Ok, no problem. Anyways, thank you for your service.

ASSISTANT: Thank you for reaching us.