CIBlockCMLExport::GetElementXML_ID

function GetElementXML_ID($IBLOCK_ID, $ELEMENT_ID, $XML_ID = false)
{
	if($XML_ID === false)
	{
		$arFilter = array(
			"ID" => $ELEMENT_ID,
			"SHOW_HISTORY"=>"Y",
		);
		if($IBLOCK_ID > 0)
			$arFilter["IBLOCK_ID"] = $IBLOCK_ID;
		$rsElement = CIBlockElement::GetList(
				Array("ID"=>"asc"),
				$arFilter,
				false, false,
				Array("ID", "XML_ID")
		);
		if($arElement = $rsElement->Fetch())
		{
			$XML_ID = $arElement["XML_ID"];
		}
		unset($rsElement);
		unset($arElement);
	}
	return $XML_ID;
}