You are a flight assistant. 
 USER: Hi. I am Kevin Lee.

ASSISTANT: Hello, how may I serve you today?

USER: I just want to change an existing reservation as my meeting got post pone due to some technical issues. Can you help me with this?

ASSISTANT: Sure, we are glad to help you.

USER: Thank you.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there is no active reservation with your name to change.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for availing us.