show next record of data from database (MySql)

<?php
$category_id=$rsctgrarticle['category_id'];
$sqlsubctgrarticle = "select * from subcategory where category_id='$category_id'";
$qrysubctgrarticle = mysql_query($sqlsubctgrarticle, $koneksi);
$hslsubindoPeriksa = mysql_num_rows($qrysubctgrarticle);
$no=1;
if (trim($hslsubindoPeriksa)!=0){
?>
<?php
$a=1;
for ($a=1;$a<=$hslsubindoPeriksa;$a=$a+2){
mysql_data_seek($qrysubctgrarticle, $a);
echo "<table border=1>";
$row = mysql_fetch_row($qrysubctgrarticle);
echo "<tr><td>$row[0]</td><td>$row[1]</td><td>$row[2]</td>";
mysql_data_seek($qrysubctgrarticle, $a+1);
$rowb = mysql_fetch_row($qrysubctgrarticle);
echo "<td>&nbsp;</td><td>$rowb[0]</td><td>$rowb[1]</td><td>$rowb[2]</td> </tr>";
}
echo "</table>";
?>