getProduct do not work in virtuemart 2.6.6

[baoquocmt159]

Hello,

I'm used Joomla 2.5.28 and VM 2.6.6, i also used :

$model = VmModel::getModel("product");
$product = $model->getProduct($virtuemart_product_id, true, true, false);

but it's not working, it return result :

    [virtuemart_product_id] => 0
    [virtuemart_vendor_id] => 0
    [product_parent_id] => 0
    [product_sku] => 0
    [product_gtin] =>
    [product_mpn] =>
    [product_name] => 0
    ....

Please take note $virtuemart_product_id is an exact number, i have checked by echo it.
Can some one help me?

Thank so much, have nice a day !