You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: I am Andrew Gonzalez. I need to change my existing reservation, Can you please help me with that?

ASSISTANT: Sure, please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there is no active reservation on your name.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you.