You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I want to change my existing reservation due to postpone of my seminar which was going to held in Charlotte. Can you help me in doing that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your good name please?

USER: Melissa Mitchell here.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for your time, there is no reservation found in your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for choosing us.