dolibarr/htdocs/product/inventory/ajax/ajax.inventory.php

<?php

require '../../../main.inc.php';
require_once DOL_DOCUMENT_ROOT.'/product/inventory/class/inventory.class.php';

$get = GETPOST('get');
$put = GETPOST('put');

    switch ($put)
    {
        case 'qty':
        	if (empty($user->rights->stock->creer)) { echo -1; exit; }

            $fk_det_inventory = GETPOST('fk_det_inventory');

            $det = new Inventorydet($db);
            if( $det->fetch( $fk_det_inventory))
            {
                $det->qty_view+=GETPOST('qty');
                $res = $det->update($user);

                echo $det->qty_view;
            }
            else
            {
                echo -2;
            }

            break;

        case 'pmp':
        	if (empty($user->rights->stock->creer) || empty($user->rights->stock->changePMP)) { echo -1; exit; }

            $fk_det_inventory = GETPOST('fk_det_inventory');

            $det = new Inventorydet($db);
            if( $det->fetch( $fk_det_inventory))
            {
                $det->new_pmp=price2num(GETPOST('pmp'));
                $det->update($user);

                echo $det->new_pmp;
            }
            else
            {
                echo -2;
            }

            break;
    }