function getOnlineIP() {  
$cip = getenv ( 'HTTP_CLIENT_IP' );  
$xip = getenv ( 'HTTP_X_FORWARDED_FOR' );  
$rip = getenv ( 'REMOTE_ADDR' );  
$srip = $_SERVER ['REMOTE_ADDR'];  
 
if ($cip && strcasecmp ( $cip, 'unknown' )) {  
$onlineip = $cip;  
} elseif ($xip && strcasecmp ( $xip, 'unknown' )) {  
$onlineip = $xip;  
} elseif ($rip && strcasecmp ( $rip, 'unknown' )) {  
$onlineip = $rip;  
} elseif ($srip && strcasecmp ( $srip, 'unknown' )) {  
$onlineip = $srip;  
}  
 
preg_match ( "/[\d\.]{7,15}/", $onlineip, $match );  
$onlineip = $match [0] ? $match [0] : 'unknown';  
 
return $onlineip;  
}