MYSQL query:

```
$sql_product = "SELECT * FROM products WHERE product_id= $product_id";
        $sql_result = $dbh->query($sql_product);

```

PHP:

```
    foreach($sql_result as $row)
        {
        $product_id=$row['product_id'];
        $product_name=$row['product_name'];
        $price=$row['price'];
        $picture=$row['picture'];

        // output
        echo "
        <div>$product_name</div>
        <div>$price</div>
        <div>
            <form action='cart.php' method='POST' id='buy'> 
                Amount: <select name='amount'>
                         <option value='1'>1</option>
                         <option value='2'>2</option>
                         <option value='3'>3</option>
                    </select>                   

            </form>
        </div>
        ";
        if (isset($_POST['amount']))
            {
            $amount = $_POST['amount'];
            echo $amount, '<br /><br />';
            }
        }
    echo "<button type='submit'class='btn btn-primary' form='buy'>Buy</button>";

```

I have a problem with the option tag in the PHP foreach loop. It's a shopping cart where there is an HTML option tag inside a form. The value from the option tag is then made into a variable called $amount. But whenever I press the button the amount changed for all the products in the shopping cart. So if I have 3 products in the cart and I want to buy 1 of the first and 2 of the second and third, then the variable $amount changes to 1 for all products. Can anyone help me out?