I want to display the selected  price, category and size on the dropdown slideingDiv. But what I have done below is not working. I have try to echo out to see if the data have been sent thought but I got nothing. Is anything wrong with my code?
Script
<script type="text/javascript">
$(document).ready(function () {
    $(".slidingDiv").hide();
    $(".show_hide").show();
    $('.show_hide').click(function () {
        $(".slidingDiv").slideToggle();
    });
});
</script>
Button
<button a href="product.php?ProdID=<?php echo $id; ?>" class="show_hide" id="button" name="button">Add to cart</a></button>
PHP
                <div class="slidingDiv"> 
                <?php
                dbconnect();
                $pid = $_POST['pid'];
                $length = $_POST["size"];
                $qty = $_POST['Qty'];
                $Category = $_POST['Category'];
                $stmt4 = $conn->prepare("
                SELECT Product.Name as ProductName, Category.Name, size, Price
                FROM item_Product, Product, Category
                WHERE Product.ProdID =:pid
                AND size= :length  AND Category.Name = :Category Limit  1");
                $stmt4->bindParam('pid',$pid);
                $stmt4->bindParam('length',$length); 
                $stmt4->bindParam('Category',$Category); 
                $stmt4->execute();
                foreach ($stmt4->fetchAll(PDO::FETCH_ASSOC) as $row4 ) {
                $product_name = $row4["ProductName"];
                $price = $row4["Price"];
                $length = $row4["size"];    
                $Category = $row4["Name"];
                ?>
                Item was added shopping bag </br>
                Name:<?php echo $row4['ProductName']; ?> </br>
                Length:<?php echo $row4['size']; ?> </br>
                Category:<?php echo $row4['Name']; ?> </br>
                Price:<?php echo $row4['Price']; ?> </br>
                <?php }
                ?>
                <a href="cart.php">View Cart</a>
                </div>