You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you today?

USER: I am Kevin Gonzalez. I want to change an existing reservation due to sudden change in my trip. Can you help me?

ASSISTANT: Sure, please wait for a moment. Sorry to say that, no reservation was found with your good name.

USER: No issue. Thank you for the help.

ASSISTANT: Thank you for opting us.