You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I am Lisa Gonzalez. I want to change an existing reservation, due to my interview got postponed.

ASSISTANT: Sure, we are glad to serve you. Please hold a moment, let me check your reservation with us.

USER: Sure.

ASSISTANT: Thanks for your valuable time, unfortunately we did not find any reservation on your name.

USER: Not an issue. Thank you.

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