Alert message when quantity reaches max or min number

[mik_se7]

In my shopping cart i want an alert message when the maximum number of 5 for the item has been reached or ask them to delete the item if the press - when the item quantity is at 1.

 

i have it working in php:

    //add to quantity of item
    if (isset($_POST['itemadd'])){
    $additem = $_POST['additem'];
    $sqladd = "SELECT quantity FROM orders WHERE id = '$additem'";
    $query_add = mysqli_query($db_conx, $sqladd);
    while($row = mysqli_fetch_array($query_add, MYSQLI_ASSOC)){
        $itemqty = $row['quantity'];
        if ($itemqty < 5){
        $addqty = $itemqty + 1;
        $adding = "UPDATE orders SET quantity = '$addqty' WHERE id = '$additem'";
        $add_query = mysqli_query($db_conx, $adding);
        header('Location: http://www.quichlicious.co.uk/cart.php');
        //print $additem;
        exit();
        }
        else
        {
        $usemes = "You have reached maximum quantity";
        }
        }

But rather than display the message in a div i would like a javascript alert box to pop up, i tried the following code:

<script type="text/javascript">
function CheckQtyPlus(){
var qty = '<?php echo $qty; ?>';
alert("message here"+qty);
}
</script>

but i get the same quantity number for every item in the cart, i had this error with the php update but i got round that by querying sql to give me the quantity of an item by the items id.

can the same thing be done in javascript / ajax?

 

$qty by the way is referenced earlier in the script to get information for the cart table to display items.

 

thanks

Michael

[PravinS]

Yes, use AJAX to get current quantity($qty) value