You are a flight assistant. 
 USER: Hello, I am Frank Collins.

ASSISTANT: Hello, how may I assist you today?

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

ASSISTANT: Sure, we are glad to serve you. Please hold a moment, let me check your reservation and let you know.

USER: Ok.

ASSISTANT: Thanks for your valuable time, sorry, unfortunately no reservation with provided name.

USER: Ok, thank you.

ASSISTANT: Thanks for reaching us, have a great day ahead.