You are a flight assistant. 
 USER: Hi. I am Charles Miller.

ASSISTANT: Hello, How can I assist you?

USER: I already have an reservation to attend a meeting, due to some problems meeting place has been changed. So I need a few changes in my reservation,. Can you help me?

ASSISTANT: Sure, Please wait a second. Sorry, No reservation found on your name.

USER: Ok.

ASSISTANT: Thank you for availing us.

USER: Thank you.