Ban Proxy Users Using Thridparty website?

Ban Proxy Users Using Thridparty website?

I use http://www.shroomery.org/ythan/proxycheck.php And Wordpress How I
can Create A plugin To Ban All users that use proxy? I know Code Must be
like this :
<?php
$ipckccc = curl_init();
curl_setopt($ipckccc,CURLOPT_URL,"http://www.shroomery.org/ythan/proxycheck.php?ip=".$_SERVER["HTTP_CF_CONNECTING_IP"]."");
curl_setopt($ipckccc,CURLOPT_RETURNTRANSFER,1);
$ipchecked=curl_exec ($ipckccc);
curl_close ($ipckccc);
?>
and This :
<?php if($ipchecked == 'Y') {
header("HTTP/1.0 404 Not Found");
die();
}else{
echo "hello";
}
?>
But how i can Deny Access Proxy From My Wordpress site?