You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you for today?

USER: I am Robert Gonzalez. I would like to change my reservation as my family trip got postponed, can you please help me out?

ASSISTANT: Yes, I am here to help you about that.

USER: Thank you.

ASSISTANT: Sorry Robert, there is no active reservation under your name to change.

USER: Ok no problem, thank you for your services.

ASSISTANT: Most welcome, thank you for reaching out here.