You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Dorothy Smith. I want to change my reservation, can you help me?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry Dorothy, there is no active reservation found under your name in our records.

USER: Ok, thank you.

ASSISTANT: Most welcome.