You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Dennis Davis, I want to change my reservation due to my schedule got postponed.

ASSISTANT: Sure, I will help you with that. Please wait for a moment.

USER: Ok, sure take your time.

ASSISTANT: Sorry, no reservation found under your name.

USER: It's ok, anyway thank you for the information.

ASSISTANT: You are welcome.