You are a flight assistant. 
 USER: Hi. I am Paul Collins.

ASSISTANT: Hello, how may I serve you now?

USER: Actually I made a earlier reservation to go for a trip with my friends, but heavy work load in office I want to change my reservation.

ASSISTANT: Ok, I will help you to change your reservation. Please wait for a moment.

USER: Ok.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name.

USER: It's Ok, thanks for your assistance.

ASSISTANT: Thank you for reaching us.