I have found away to block the IP using PHP.
Code:
<meta http-equiv='refresh' content='0; URL=http://www.skgastonia.com/banned.htm'> 

<? $incomingIp = getenv(REMOTE_ADDR);

if($incomingIp == "64.92.76.38"){
echo " ";
}?>
The reason I need to do this is an employee's ex wife keeps coming in and putting all kinds of stuff in our guestbook. I did take it down for the moment but would like to return it. I am also pretty sure she has a very basic understanding of computers so I don't think she could spoof the IP or anything.

I couldn't make it a restricted site because we sell products from it.

Oh well thanks for everyone's help.