You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: John Taylor here.

ASSISTANT: John, how can I guide you today?

USER: My interview got postponed, so I want to change my reservation. Could you help me out?

ASSISTANT: Sure, I will help you with that. Please wait for a while.

USER: Ok.

ASSISTANT: Sorry, no reservation found by your name.

USER: It's ok, thank you for helping me.

ASSISTANT: You are welcome.