You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I need to change my existing reservation due to postpone of my conference. Could you please help me?

ASSISTANT: Sure, please share your name.

USER: Sure, I am Jeffery Brown.

ASSISTANT: Please wait, I will revert back to you soon.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, we didn't find any reservation on your name to change.

USER: No worries, thank you for the information.

ASSISTANT: Thank you.