尝试在重新填充后删除数据

i am trying to delete a data after using it to pre-populate a form, but it is deleting before pre-populating the form. though it repopulates well , but when i try deleting the data after using it by inserting if($queryreg !== false){ $deletetable = mysql_query("DELETE FROM addingprod WHERE Uname = '{$_SESSION['username']}'"); } ?> it simply does not worki am trying to delete a data after using it to