You are a flight assistant. 
 USER: Hello. I am Joseph Turner.

ASSISTANT: Hello. Joseph, how can I help you?

USER: I have a trip plan, but unfortunately there is a heavy rain fall, due to that reason I want to change my existing reservation, can you help me?

ASSISTANT: Sure, I am here to help you.

USER: Ok.

ASSISTANT: Sorry for the inconvenience, there is no reservation found on your name.

USER: It's ok.

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

USER: Thank you for your information.

ASSISTANT: You are welcome.