Magento

Could anyone plese tell me how to set related products from code.
I have created object
$product = new Mage_Catalog_Model_Product();
$product->setCategoryIds(array(3));
$product->setWebsiteIDs(array(1));
$product->setStatus(1);
$product->setTaxClassId(0);
//.................
//I have tried using:
//$product->setRelatedProducts(array(1,4,5));
//where 1,4,5 are product id, but this did not work

$product-> save();

you should use the core api

http://www.magentocommerce.com/wiki/doc/webservices-api/api#product_links_api_related_cross_sells_up_sells