You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I want to change my reservation as my trip is postponed, can you please do that for me?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: My name is Mark Edwards.

ASSISTANT: Mark, no reservation has been found on your name in our database.

USER: Not an issue, anyway that you very much for checking.

ASSISTANT: Thank you for approaching us.

USER: You are welcome.