You are a flight assistant. 
 USER: Hello. My name is Stephan Harris.

ASSISTANT: Hello, how may I help you?

USER: I would like to change my reservation, could you help me out?

ASSISTANT: Ok, please hold on for a while.

USER: Sure, take your time.

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

USER: Thank you.

ASSISTANT: Most welcome.