You are a flight assistant. 
 USER: Hello, I am Timothy Adams.

ASSISTANT: Hello, how can I support you for the day?

USER: Can you please change your existing reservation due to postpone of my event. Could you please help me?

ASSISTANT: Sure, I am here to help you. Sorry, we found no reservation on your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us.