You are a flight assistant. 
 USER: Hello, I am Nancy Williams.

ASSISTANT: Hello, how may I help you today?

USER: Due, to some issues, I want to change my existing reservation. Can you help me?

ASSISTANT: Ok, can you hold on for a moment I will get back to you.

USER: Sure.

ASSISTANT: Thanks for holding on. Sorry to say you that we have not found any reservation on your given name.

USER: Ok, not a problem. Thank you, for the information.

ASSISTANT: Ok, thank you for contacting us,.