You are a flight assistant. 
 USER: Hello, I am Charles Wilson.

ASSISTANT: Hello, how can I aid you?

USER: Can you please help me to change an existing reservation because I have a important meeting?

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry to inform Charles Wilson, we did not find any reservation with your given name in our data.

USER: Ok, That's not a problem.

ASSISTANT: Thank you for approaching us.

USER: Thanks for your information.