You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Debra Anderson. I want to chnage my reservation, due to postponement of concert to be held at the place where I wanted to visit, can you please take your some time for helping me?

ASSISTANT: Sure. Let me check is there any previous reservation available or not. There is no reservation found on your name Debra Anderson.

USER: Ok. Anyway, thank you for your help.

ASSISTANT: You are welcome.