You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

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

ASSISTANT: Sure, I am here to help you. Could you please provide your name to check your reservation status?

USER: Sure, my name is Karen Green.

ASSISTANT: Ok, please hold on for a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry to say, there is no reservation on your name in my database.

USER: Ok, that's fine.

ASSISTANT: Thank you for reaching us, have a nice day.

USER: Anyways, thank you for your service.