MySQL join...

$sel_g = mysql_query("SELECT galeria.id FROM galeria_clanky LEFT JOIN galeria ON galeria_clanky.galeria_id=galeria.id WHERE galeria_clanky.clanok_id='$id'");
while($res_g = mysql_fetch_assoc($sel_g))
{
    $res_g["id"];       
}

CREATE TABLE IF NOT EXISTS `galeria` (
  `id` int(11) NOT NULL auto_increment,
  `publikovat` varchar(250) collate utf8_czech_ci NOT NULL,
  `nazov_sk` varchar(200) collate utf8_czech_ci NOT NULL,
  `nazov_en` varchar(200) collate utf8_czech_ci NOT NULL,
  `nazov_de` varchar(200) collate utf8_czech_ci NOT NULL,
  `obsah_sk` text collate utf8_czech_ci NOT NULL,
  `obsah_en` text collate utf8_czech_ci NOT NULL,
  `obsah_de` text collate utf8_czech_ci NOT NULL,
  `obrazok` varchar(250) collate utf8_czech_ci NOT NULL,
  `datum` datetime NOT NULL,
  `datum_uprav` datetime NOT NULL,
  `upravil` int(10) NOT NULL,
  PRIMARY KEY  (`id`)
)


CREATE TABLE IF NOT EXISTS `galeria_clanky` (
  `id` int(11) NOT NULL auto_increment,
  `clanok_id` int(11) NOT NULL,
  `galeria_id` int(11) NOT NULL,
  PRIMARY KEY  (`id`)
)



INSERT INTO `galeria_clanky` (`id`, `clanok_id`, `galeria_id`) VALUES
(1, 1, 1)