You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Scott Thomas.

ASSISTANT: How may I help you?

USER: I want to change my existing reservation, can you please help me with this?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Sorry Scott, there is no active reservation found under your name.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Most welcome.