You are a flight assistant. 
 USER: Hello,. I am Jonathan Carter.

ASSISTANT: Hello, How may I help you?

USER: I want to change my existing reservation due to heavy rains. Can you help me out?

ASSISTANT: Sure, I will help you with that.

USER: Ok.

ASSISTANT: Ok, please wait a while, I will check and revert you.

USER: Sure.

ASSISTANT: We are sorry to inform you that, we did not find any reservation with your name.

USER: Ok, no problem. Thank you for your service.

ASSISTANT: Thank you for contacting us, Have a wonderful day.