แบ่งหน้าไม่ได้ครับ TT^TT Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in

<?
	$host = "localhost";
	$user = "root";
	$pass = "123456";
	$db = "otop";
	$table = "Products";
	$dblink = mysql_connect($host,$user,$pass);

	$connection_id = $dblink;

	$page = (isset($_GET['page']))? intval($_GET['page']) : 1;
	$limit_end = 5;
	$limit_start = ($page-1)*$limit_end;

	$sql = "SELECT * FROM $table;";
	$query_id = mysql_query($sql . " LIMIT " . $limit_start. "," . $limit_end, $connection_id);
	mysql_query("SET NAMES UTF8");
	mysql_query("USE $db;");
	$count = mysql_num_rows($query_id);
	$total = mysql_num_rows(mysql_query($sql, $connection_id));

	?>
	<br />
    <?
		if($total > 0){
		while($p = mysql_fetch_array($query_id)) {
	?>
	<table width="600" height="20" border="0">
	  <tr valign="top">
	    <th width="150" scope="col"><img src="read_image.php?ProductID=<? echo $p['ProductID']; ?>"></th>
	    <th width="440" class="left" scope="col"><table width="440" border="0">
              <tr>
                <th width="434" height="20" bgcolor="#FFFFCC" scope="col"><? echo $p['ProductName']; ?></th>
              </tr>
            </table>
	        &nbsp;<? echo $p['Description']; ?><br />
	      <br />
	      <p>&nbsp;ราคา : <? echo $p['UnitPrice']; ?> บาท</p>
            <form id="form1" name="form1" method="post" action="">
              <p align="right">จำนวน <input name="txtNum" type="text" id="txtNum" size="5" value="1"/> ชิ้น</label>
              <a href="showcart?pid=<? echo $p['ProductID']; ?>"><img src="../Image/cart.gif" width="16" height="16" border="0" /></a>
			  <a href="showcart?pid=<? echo $p['ProductID']; ?>">หยิบใส่รถเข็ญ</a></p>
          </form></th>
      </tr>
</table>
    <?
		}
		echo "\n<div style=\"float:left;\">Page : " . page_navi($page, $limit_end, 4, $total, $send) . " </div><div style=\"float:right;\">[" . ($limit_start+1) . "-" . ($limit_start+$count) . "] of <strong>" . $total . "</strong></div>";
}
?>