Вывод полей инфоблока

$arSelect = Array("ID", "NAME", "PREVIEW_PICTURE", "DETAIL_PICTURE");
$arFilter = Array("IBLOCK_ID"=>"5", "ACTIVE"=>"Y");
$res = CIBlockElement::GetList(Array(), $arFilter, false, false, $arSelect);
while($ob = $res->GetNextElement())
{
  $arFields = $ob->GetFields();
  print_r($arFields);
}