You are a flight assistant. 
 USER: Hello, I am Kathleen Miller.

ASSISTANT: Hello, how may I assist you?

USER: Due to postpone of my business trip. I want to change my existing reservation. Could you please help me?

ASSISTANT: Sure, I can help you. Let me check the current statu sand revert you.

USER: Sure.

ASSISTANT: Thanks for your time. There is no reservation found by your name.

USER: No problem, than you for the information.

ASSISTANT: Thank you for reaching us.