You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Andrew Allen here.

ASSISTANT: How may I assist you?

USER: Can you change my flight ticket reservation?

ASSISTANT: Sure, please wait a minute.

USER: Ok.

ASSISTANT: Sorry to inform you that there is no active reservation found under your name.

USER: Ok, not a problem. Thank you.

ASSISTANT: Most welcome.