<?php
require_once '../app/Mage.php';  
umask(0);  
Mage::app('default');
 
 
try{
	$id_product = 17863;
	$nom_attribut = 'manufacturer';
 
	$product = Mage::getModel('catalog/product')->load($id_product);
	$attributes = $product->getAttributes();
 
	$valeur_attribut = null;
	if(array_key_exists($nom_attribut , $attributes)){
		$o_attributes = $attributes["{$nom_attribut}"];		
		$valeur_attribut = $o_attributes->getFrontend()->getValue($product);
	}
	echo $valeur_attribut; 
 
	}catch (Exception $e){
		Zend_Debug::dump($e->getMessage());
 
	}
?>

<?php
require_once '../app/Mage.php';  
umask(0);  
Mage::app('default');
 
try{
	$id_product = 17863;
	$nom_attribut = 'marque';
 
	$product = Mage::getModel('catalog/product')->load($id_product);
 
	echo $product->getResource()->getAttribute($nom_attribut)->getFrontend()->getValue($product);
 
}catch (Exception $e){
	Zend_Debug::dump($e->getMessage());
}
?>