Have you tried it? Well then you would know, here is your script except maybe you can explain why you want the $GET['abc']; Here is your script and it will run but not sure what you want to really do.
<?php
$ipaddress=$_SERVER['REMOTE_ADDR'];
$_GET['abc'];
?>
<html>
<head>
<title>this is a test</title>
</head>
<body>Welcome to this page... I see you are coming from the IP address of <?php echo $ipaddress ?> Ha ha ha! You are caught on this site.
</body>
</html>