Undefined variable: ATC_itemQuantity

Hi I am having a problem with my add to cart buttons

Notice: Undefined variable: ATC_itemQuantity in /albionwineshippers.co.uk\httpdocs\startlist.php on line 137

i dont understand why its not getting set, as in firebug it shows the correct ID being posted along with the quantity:

Posted Vars from firebug are:
eCart1_1_ATC Add to Cart
eCart1_1_ATC.x 43
eCart1_1_ATC.y 17
eCart1_1_ID_Add 53
eCart1_1_Quantity_Add 1


I have attached the php file in a zip, the page can be viewed at:
albion.base5.eu (its on an index page and included using framework

the standalone page is here:
startlist.php

here is the code generated by ecart:

<?php
// WA eCart AddToCart
if (isset($_POST["eCart1_1_ATC"]) || isset($_POST["eCart1_1_ATC_x"])) {
$ATC_itemID = $_POST["eCart1_1_ID_Add"];
$ATC_AddIfIn = 0;
$ATC_RedirectAfter = "";
$ATC_RedirectIfIn = "";
if (isset($totalRows_rs_products) && $totalRows_rs_products > 0) {
$row_rs_products = WAEC_findRecordMySQL($rs_products, "id_prd", $ATC_itemID);
if ($row_rs_products) {
$ATC_itemName = "".$row_rs_products['name_prd'] ."";// column binding
$ATC_itemDescription = "".$row_rs_products['shortdesc_prd'] ."";// column binding
$ATC_itemThumbnail = "".$row_rs_products['image_prd'] ."";// column binding
$ATC_itemWeight = floatval("".$row_rs_products['weight_prd'] ."");// column binding
$ATC_itemQuantity = "".$_POST["eCart1_1_Quantity_Add"] ."";// column binding
$ATC_itemPrice = floatval("".$row_rs_products['price_prd'] ."");// column binding
$ATC_itemBottles = floatval("".$row_rs_products['bottles_prd'] ."");// column binding
$ATC_itemOnSale = "".$row_rs_products['onsale_prd'] ."";// column binding
$ATC_itemSalePrice = floatval("".$row_rs_products['saleprice_prd'] ."");// column binding
mysql_data_seek($rs_products, 0);
$row_rs_products = mysql_fetch_assoc($rs_products);
}
}
$ATC_itemQuantity = floatval($ATC_itemQuantity);
if (is_numeric($ATC_itemQuantity) && $ATC_itemQuantity != 0) {
$eCart1->AddToCart($ATC_AddIfIn, $ATC_RedirectIfIn, $ATC_itemID, $ATC_itemName, $ATC_itemDescription, $ATC_itemThumbnail, $ATC_itemWeight, $ATC_itemQuantity, $ATC_itemPrice, $ATC_itemBottles, $ATC_itemOnSale, $ATC_itemSalePrice);
if ($ATC_RedirectAfter != "" && $eCart1->redirStr == "") {
$eCart1->redirStr = $ATC_RedirectAfter;
}
if (isset($_SERVER['QUERY_STRING']) && $_SERVER['QUERY_STRING'] != "") {
$_SESSION['WAEC_ContinueRedirect'] = $_SERVER['PHP_SELF']."?".$_SERVER['QUERY_STRING'];
}
else {
$_SESSION['WAEC_ContinueRedirect'] = $_SERVER['PHP_SELF'];
}
}
}
?>
<?php
// WA eCart Redirect
if ($eCart1->redirStr != "") {
session_commit();
header("Location: ".$eCart1->redirStr);
}
?>