You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am Michael Gonzalez. I want to change my existing reservation, as my cousin's wedding got postponed.Can you please help me with this?

ASSISTANT: Sure, I will help you. Sorry, there is no reservation with your name to change.

USER: Ok, not an issue. Thank you for your time.

ASSISTANT: Thank you for consulting us, have a great day.