You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I am Joseph Allen.

ASSISTANT: Glad to meet you Allen.

USER: I want to change my reservation due to heavy rain fall in my place, can you help me in that?

ASSISTANT: Sure, I am happy to help you with that. Please be hold on for a moment to check existence of reservation.

USER: Sure.

ASSISTANT: Thank you for waiting. Sorry Allen, there is no reservation found under your name to change.

USER: That's ok, might be my brother has changed. Thank you for your help.

ASSISTANT: May be yes. Thank you for choosing us, have a great day.