PHP购物车产品ID

So, I'm trying to create a simple shopping cart for my php class. I've come to a stop because I noticed the product IDs aren't working the correct way. Right now, I have an info button that should pull up information from a database, but it seems it keeps pulling the same information for every product I select. I have 20 products, with a ProductID column going from 1-20, but it almost seems like it assigns every product to "1". For now, I just want to pull up the info when I hit the info button, as I'm sure solving that will help with the rest. Here is the code:

<?php

session_start();
require_once 'DBLogin.php';

echo "<form action='Catalogue.php' method='Post'>";

$sql = "SELECT * FROM ACME.Products";
$result = mysql_query($sql);

echo "<select name='Select_Product'>";
while ($row = mysql_fetch_array($result)) {
    echo "Please select a product: <option value='" . $row['ProductID'] .     "'>" . $row['Name'] . "</option>";
}
echo "</select>";

echo <<<HTML

<table>
<tr> <td>
<input id="button_Add" type="submit" value="Add" name="action"/>                          
</td> <td> <input id="button_Remove"
type="submit" value="Remove" name="action"/>
</td> <td> <input id="button_empty"
type="submit" value="Empty" name="action"/>
</td> <td> <input id="button_Info"
type="submit" value="Info" name="action"/>
</td> </tr>
</table>
</form>
HTML;

//code to attempt to pull the info
$product_id = $_POST['Select_Product']; 
$action = $_POST['action'];

switch ($action) {
    case "Add":
        echo $_SESSION['cart'][$product_id]++;
        break;
    case "Remove":
        $_SESSION['cart'][$product_id]--;
        if($_SESSION['cart'][$product_id] == 0)
        unset($_SESSION['cart'][$product_id]);
        break;
    case "Empty":
        unset($_SESSION['cart']);
        break;
    case "Info":
        $sql = "SELECT * FROM ACME.Products";
        $result = mysql_query($sql);
        $row = mysql_fetch_array($result);
        echo "<table>";
        echo "<tr><td>Name</td><td>Description</td ><td>Price</td><td>Image</td>     </tr>";
        echo "<td>" . $row['Name'] . "</td>";
        echo "<td>". $row['Description'] . "</td>";
        echo "<td>". $row['Price'] . "</td>";
        echo "<td align=\"center\"><img alt=\"\" src=\"productImages/".  $product_id . ".jpg\ width=\"120\" height=\"120\"/></td></tr>";
        echo "</table>";
        break;
}

Here is the link to the site so you can see what's going on too: http://ec2-52-24-105-81.us-west-2.compute.amazonaws.com/Catalogue.php

Any help would be greatly appreciated!

you forgot where clause

case "Info":
    $sql = "SELECT * FROM ACME.Products Where id = $product_id Limit 1";