You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I support you?

USER: Due to sudden change in weather conditions, I need to change my existing reservation. Can you help me with that?

ASSISTANT: I can help you with that. May I know your name?

USER: My name is Charles Gonzalez.

ASSISTANT: Please wait a minute. I will revert you.

USER: Sure.

ASSISTANT: Thanks for your time. there was no reservation found on your name.

USER: Ok, Thanks for your information.

ASSISTANT: Thank you for choosing us.