Функция вывода кнопки купить - [VM1] Общие вопросы и ошибки

<?php if( !defined( '_VALID_MOS' ) && !defined( '_JEXEC' ) ) die( 'Direct Access to '.basename(__FILE__).' is not allowed.' ); ?>

<div class="vmCartContainer">
    
<?php
mm_showMyFileName(__FILE__);
// This function lists all product children ( = Items)
// or, when not children are defined, the product_id
// SO LEAVE THIS IN HERE!
list($html,$children) = $ps_product_attribute->list_attribute( ( $product_parent_id > 0 )  ? $product_parent_id : $product_id );

if ($children != "multi") { 

    if( CHECK_STOCK == '1' && ( $product_in_stock  < 1 ) ) {
     	$notify = true;
    } else {
    	$notify = false;
    }

	
?>
    <form action="<?php echo $mm_action_url ?>index.php" method="post" name="addtocart" id="<?php echo uniqid('addtocart_')?>" class="addtocart_form" <?php if( $this->get_cfg( 'useAjaxCartActions', 1 ) && !$notify ) { echo 'onsubmit="handleAddToCart( this.id );return false;"'; } ?>>

	
	
<?php
}
echo $html;

if (USE_AS_CATALOGUE != '1' && $product_price != "" && !stristr( $product_price, $VM_LANG->_('PHPSHOP_PRODUCT_CALL') )) {
	?>
        <?php if ($children != "multi") { ?> 
    <div style="float: right;vertical-align: middle;"> <?php 
    if ($children == "drop") { 
    	echo $ps_product_attribute->show_quantity_box($product_id,$product_id);
    } 
    if ($children == "radio") {
		echo $ps_product_attribute->show_radio_quantity_box();
    }
    $button_lbl = $VM_LANG->_('PHPSHOP_CART_ADD_TO');
    $button_cls = 'addtocart_button';
    if( CHECK_STOCK == '1' && ( $product_in_stock < 1) ) {
     	$button_lbl = $VM_LANG->_('VM_CART_NOTIFY');
     	$button_cls = 'notify_button';
    }
    ?>    
    <input type="submit" class="<?php echo $button_cls ?>" value="<?php echo $button_lbl ?>" title="<?php echo $button_lbl ?>" />
    </div>
    <?php  } ?>    
    <input type="hidden" name="flypage" value="shop.<?php echo $flypage ?>" />
	<input type="hidden" name="page" value="shop.cart" />
    <input type="hidden" name="manufacturer_id" value="<?php echo $manufacturer_id ?>" />
    <input type="hidden" name="category_id" value="<?php echo $category_id ?>" />
    <input type="hidden" name="func" value="cartAdd" />
    <input type="hidden" name="option" value="<?php echo $option ?>" />
    <input type="hidden" name="Itemid" value="<?php echo $Itemid ?>" />
    <input type="hidden" name="set_price[]" value="" />
    <input type="hidden" name="adjust_price[]" value="" />
    <input type="hidden" name="master_product[]" value="" />
    <?php
}
if ($children != "multi") { ?>
	</form>
<?php 
} 
    if($children == "radio") { ?>
    
    <script language="JavaScript" type="text/javascript">//<![CDATA[
    function alterQuantity(myForm) {
        for (i=0;i<myForm.selItem.length;i++){
            setQuantity = myForm.elements['quantity'];
            selected = myForm.elements['selItem'];
            j = selected[i].id.substr(7);
            k= document.getElementById('quantity' + j);
            if (selected[i].checked==true){
                k.value = myForm.quantity_adjust.value; }
            else {
                k.value  = 0;
            }
        }
    }
	//]]>   
	</script>
<?php } ?>
</div>

if( CHECK_STOCK == '1' && ( $product_in_stock  < 1 && $product_in_stock2  < 1 ) ) {

if( CHECK_STOCK == '1' && ( $product_in_stock < 1 && $product_in_stock2 < 1) ) {

if( CHECK_STOCK == '1' && ( $product_in_stock or $product_in_stock2 ) ) {
echo 'есть на складах';
} else {
echo 'уведомить меня';
}

<input type="hidden" name="func" value="cartadd"/>