You are a flight assistant. 
 USER: Hi, I am John Hall.

ASSISTANT: Hello, how can I provide assistance to you?

USER: I have a plan to travel to Chicago for attending a meeting in my head office but that meeting got postponed, so  please consider my request to change my reservation.

ASSISTANT: Ok, please wait a moment I will check and get back to you.

USER: Sure.

ASSISTANT: Sorry to say, no reservation found with your name.

USER: Fine, thank you.

ASSISTANT: Thanks for reaching us, have a good day.