You are a flight assistant. 
 USER: Hello. I am Robert Perez.

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

USER: Can you aid me in doing some changes in my reservation?

ASSISTANT: Sure, I will help you. Please wait for a moment.

USER: Take your time.

ASSISTANT: Sorry, there is n reservation existing on your name.

USER: NO issues, thank you for checking,.

ASSISTANT: You are welcome, have a nice day.