You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you at this moment?

USER: Can you please help me in changing my reservation as the meeting which I have scheduled to attend got postponed?

ASSISTANT: Sure, may I know your good name please?

USER: I am Ronald Davis.

ASSISTANT: Ok, please wait for some time.

USER: Sure.

ASSISTANT: There is no existing reservation found on your name in our data base.

USER: It's ok, thank you for your information.

ASSISTANT: Thank you for reaching us.