Update this:
<?php
// WA eCart Trigger AddToCart
if (isset($_POST["unstyled"]) || isset($_POST["unstyled_x"])){
$cart = $eCart1;
$ATC_itemID = "0";
to:
<?php
@session_start();
?>
<?php
// WA eCart Trigger AddToCart
if (isset($_POST["unstyled"]) || isset($_POST["unstyled_x"])){
$cart = $eCart1;
$ATC_itemID = "".($WADAproductAdd->getColumnVal("ProductID")) ."";