$sql = " select wr_id from g5_write_TEST02 where wr_subject IN(
select wr_subject from g5_write_TEST02 group by wr_subject HAVING COUNT(*) > 1
) and wr_is_comment = '0' order by wr_datetime desc ";
$result = sql_query($sql);
for($i=0; $row=sql_fetch_array($result); $i++){
if($i > 0)
sql_query(" delete from g5_write_TEST02 where wr_id = '{$row['wr_id']}' ")
}