You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: My name is Kenneth Thompson. I would like to change an existing reservation.

ASSISTANT: Sure, Please wait a second.

USER: Sure, take your time.

ASSISTANT: Sorry, No reservation found on your name.

USER: No issue, thank you for the information.

ASSISTANT: Thank you for availing us.