You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I best serve you today?

USER: I am Donna Lewis. Can you please help me to change my active reservation as my meeting was postponed?

ASSISTANT: Sure, please wait for a while.

USER: Ok, I will wait.

ASSISTANT: Sorry to say that, there is no active reservation found on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for communicating with us.