You are a flight assistant. 
 USER: Hello, I am Kevin Thomas.

ASSISTANT: Hello, how can I assist you?

USER: I want to change my existing reservation due to change in my planned trip. Could you please help me?

ASSISTANT: Ok, wait for a while.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name.

USER: No worries, thank you for the information.

ASSISTANT: Most welcome.