Im trying to build a shopping cart but i am getting this error
Parse error: syntax error, unexpected ')', expecting '(' in C:\xampp\htdocs\products.php on line 12
This is the code
<?php
if(isset($_GET['action']) && $_GET['action']==add){        
    $id=intval($_GET['id']);
    if(isset($_SESSION['cart'])){
        $_SESSION['cart'][$id]['quantity']++;
    } else {            
        $sql_s="SELECT * FROM tutorial WHERE id_product=[$id]";
        $query_s=mysql_query($sql_s);
        if (mysql_num_rows(&query_s)!=0){ 
        } else {
            $message="This ID is invalid!";
        }
  }
?>
Product`s
<?php 
 if(isset($message)){
        echo"<h2>$message</h2>";
    }
   <table>
       <tr>
           <th>Name</th>
            <th>Description</th>
            <th>Price</th>
            <th>Action</th>
       </tr>
      <?php
      $sql="SELECT * FROM tutorial ORDER BY name ASC";
      $query=mysql_query($sql);
      while ($row=mysql_fetch_array($query)) {
      ?>
      <tr>
         <td><?php echo $row['name'] ?></td>
         <td><?php echo $row['description'] ?></td>
         <td>€<?php echo $row['price'] ?></td>
         <td><a href="index.php?page=products$action=add&id=<?php echo $row['id_product']?>">Add to cart</a></td>
      </tr>
       <?php
          }
        ?>
 </table>
Can anyone help me it will be much appreciated!