I am trying to test the ArdGuest - Free PHP Guestbook Script on a production server before installing on website.
I get the fllowing PHP Warning: eregi() [<a href='function.eregi'>function.eregi</a>]: REG_EMPTY in C:\CustomerData\shopdemo.webitry.net\index.php on line 601. I have marked line 601 in the code below.

function is_spam($string) {
	            $data = "spamwords.dat";
	            $is_spam = false;
	  if (file_exists($data)) {
		$spamword = file($data);
		$jmlrec = count($spamword);
		for ($i=0; $i<$jmlrec; $i++) {
		$spamword[$i] = trim($spamword[$i]);
line 601	  if (eregi($spamword[$i],$string)) {
		$is_spam = true;
What is causing the error and how can it be corrected?