Manufacturers_name in product Title

Hi all,
I am trying to insert manufacturers_name in product's title but so far nothing)) To be honest, I am a noob in php so I would appreciate if someone could help me with that.

so I looked into meta_tags.php and edited these lines:

$sql= "select pd.products_name, p.products_model, p.products_price_sorter, p.products_tax_class_id,
p.metatags_title_status, p.metatags_products_name_status, p.metatags_model_status,
p.products_id, p.metatags_price_status, p.metatags_title_tagline_status,** p.manufacturers_id,
m.manufacturers_name, m.manufacturers_id,**
pd.products_description, p.product_is_free, p.product_is_call,
mtpd.metatags_title, mtpd.metatags_keywords, mtpd.metatags_description
from (" . TABLE_PRODUCTS . " p, " . TABLE_MANUFACTURERS . " m, " . TABLE_PRODUCTS_DESCRIPTION . " pd) left join " . TABLE_META_TAGS_PRODUCTS_DESCRIPTION . " mtpd on mtpd.products_id = p.products_id and mtpd.language_id = '" . (int)$_SESSION['languages_id'] . "'
where p.products_id = '" . (int)$_GET['products_id'] . "'
** and p.manufacturers_id = '" . (int)$_GET['manufacturers_id'] . "'**
and p.products_id = pd.products_id
and pd.language_id = '" . (int)$_SESSION['languages_id'] . "'";

and

if (META_TAG_INCLUDE_MODEL == '1' && zen_not_null($product_info_metatags->fields['products_model'])) {
$meta_products_name = $product_info_metatags->fields['products_name'] . ' ' . $product_info_metatags->fields['products_model'] . ' ' . $product_info_metatags->fields['manufacturers_name'];

But so far I don't get the result I want. Could somebody help me figure out what I am missing?
Thank you!