merhaba arkadaşlar siteme link ufaltma sistemi kuruyorum fakat linki girip kelimeyi yazdıktan sonra yeni link al dediğimde şöyle bir hata alıyorum :

Warning: mysql_fetch_assoc(): supplied argument is not a valid MySQL result resource in /home/hgurcan/public_html/urll/index.php on line 18
Yeni Link: html:// xxxxxxxx/xx/xx

index.php dosyam :
<?php
	define('mysql_hostname', 'xxxxxxx');
	define('mysql_username', 'xxxxxxx');
	define('mysql_password', 'xxxxxxx');
	define('mysql_database', 'xxxxxxx');
	ob_start('relink');
	$root = "http://$_SERVER[HTTP_HOST]" . ereg_replace('/$', '', dirname($_SERVER['PHP_SELF'])) . '/';
	$action = $_GET['action'] ? $_GET['action'] : ($_POST['action'] ? $_POST['action'] : '');
	$connection = @mysql_connect(mysql_hostname, mysql_username, mysql_password) && @mysql_select_db(mysql_database) || die('<code>' . mysql_error() . '</code>');
	switch ($action) {
		case 'generate_url':
			$parsed = @parse_url($_POST['url']);
			if ($parsed && strlen($_POST['url']) && ereg('\.', $_POST['url'])) {
				if (eregi('^[a-z0-9-]+$', $_POST['tag'])) {
					$tag = $_POST['tag'];
					$sql = "SELECT * FROM `urls` WHERE `url_tag` = '$tag' OR `url_id` = '$tag'";
					$q = mysql_query($sql);
					$n = mysql_fetch_assoc($q);
					if ($n) {
						$cancel = true;
					}
				}
				if (!$cancel) {
					$url = ($parsed['scheme'] ? '' : 'http://') . (get_magic_quotes_gpc() ? mysql_real_escape_string(stripslashes($_POST['url'])) : mysql_real_escape_string($_POST['url']));
					$sql = "INSERT INTO `urls` (`url_location`, `url_tag`) VALUES ('$url', '$_POST[tag]')";
					$q = mysql_query($sql);
					$id = mysql_insert_id();
					if (!$tag) {
						$result = '<strong>Yeni Link</strong>: <a href="' . $root . $id . '/">' . $root .  $id . '/</a> !';
					} else {
						$result = '<strong>Yeni Link</strong>: <a href="' . $root . $tag . '/">' . $root .  $tag . '/</a> !';
					}
				} else {
					if (ereg('^[0-9]+$', $_POST['tag'])) {
						$result = 'That tag is reserved for the system!';
					} else {
						$result = 'Tag unavailable!';
					}
				}
			} else {
				$result = 'Put in a <strong>real URL</strong> please!';
			}
			if ((bool) $_POST['javascript']) {
				header('Content-Type: text/plain');
				die($result);
			}
		break;
		case 'redirect':
			if (is_numeric($_GET['id']) || eregi('^[a-z0-9-]+$', $_GET['tag'])) {
				if (!$_GET['tag']) {
					$sql = "SELECT * FROM `urls` WHERE `url_id` = $_GET[id]";
				} else {
					$sql = "SELECT * FROM `urls` WHERE `url_tag` = '$_GET[tag]'";
				}
				$q = mysql_query($sql);
				$r = mysql_fetch_assoc($q);
				header("Location: $r[url_location]");
				exit;
			} else {
				header("Location: $root");
				exit;
			}
		break;
	}
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
	<head>
		<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
		<meta name="description" content="Link Ufaltma Servisi" />
		<meta name="keywords" content="link,ufalt,kısalt,servis" />
		<title>Link Ufaltma Servisi</title>
		<link href="/css/main.css" rel="stylesheet" />
		<link href="/img/favicon.png" rel="shortcut icon" />
		<script language="javascript" type="text/javascript">
			root = '<?php echo ereg_replace('/$', '', $root); ?>';
		</script>
		<script language="javascript" type="text/javascript" src="/js/main.js"></script>
	</head>
	<body>
		<div id="header">
			<center><h1><a href="/" title="Link Ufalt">Link Ufaltma Servisi</a></h1></center>
			
		</div>
		<form method="post" action="/" id="form">
			<input type="hidden" name="action" value="generate_url" />
			<h3><label for="url">Link</label></h3>
			<input type="text" name="url" id="url" class="input" />
			<h3 class="normal"><label for="tag">Kelime</label></h3>
			<input type="text" name="tag" id="tag" class="input" />
			<h3><label for="submit">Yeni Linki Al</label></h3>
			<input type="submit" value="Yeni Linki Al" id="submit" class="button" />
			<div id="result"><?php echo $result ? $result : ''; ?></div>
		</form><br><br><br><br><br><br><br><br><br><br><br>
		<center><div id="footer"><a href="http://www.arsivlerim.com" onclick="add_plugin(); return false;">Powered By Arsivlerim</a></div></center>
	</body>
</html>
<?php
	function relink ($buffer) {
		global $root;
		return preg_replace('#(href|src|action)="/#i', '\\1="' . $root, $buffer);
	}
?>
yardımlarınızı bekliyorum.