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

ASSISTANT: Hello. How may I assist you?

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. Can you help me with it please?

ASSISTANT: Sure, I will help you.

USER:    Thank you.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: There is no reservation on your name.

USER: That's ok.

ASSISTANT: Thank you so much.

USER: Thank you for the response.