$IP = $_SERVER['REMOTE_ADDR']; 
$PORT = $_SERVER['REMOTE_PORT']; 
$test_page = 'http://google.com'; 
   $cUrl = curl_init(); 
   curl_setopt($cUrl, CURLOPT_URL, $test_page); 
   curl_setopt($cUrl, CURLOPT_RETURNTRANSFER, 1); 
   curl_setopt($cUrl, CURLOPT_TIMEOUT, '10'); 
   curl_setopt($cUrl, CURLOPT_NOBODY, 1); 
   curl_setopt($cUrl, CURLOPT_PROXY, $IP.':'.$PORT); 
   $pageContent = trim(curl_exec($cUrl)); 
   curl_close($cUrl); 
if (empty($pageContent)) 
   echo '<br>this is not a proxy '.$IP.':'.$PORT.'<br>'; 
else echo '<br>this is a proxy '.$IP.':'.$PORT.'<br>';