Mine

<?
$secust = mysql_query("SELECT id, kategoriadi FROM kategoriler");

while($kayitust = mysql_fetch_object($secust)) {

	$ustid = $kayitust->id;
	
	echo "<li><a href='#'>".$kayitust->kategoriadi."</a><ul>";
	
	$secalt = mysql_query("SELECT id, altkategoriadi FROM altkategoriler WHERE katid = '$ustid'");
	
	while($kayitalt = mysql_fetch_object($secalt)) {
		echo "<li><a href='products.php?kategori=".$kayitalt->id."'>".$kayitalt->altkategoriadi."</a></li>";
		
	}
        echo "</ul></li>";

}
?>