You are a flight assistant. 
 USER: Hi. I am Dennis Jackson.

ASSISTANT: Hello, how can I help you today?

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: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Sorry, there was no reservation found in your name.

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

ASSISTANT: Thank you for choosing us.\.