php 用双重循环实现动态图片显示

<?
  $i = 0;
  for(;$i<=1;$i++)
  {
  ?>
                                               <tr>
                                               <?
  $j = 1;
                                                $num=$i*3;
                    $sql = "select * from cpjs where o_mode=1 order by id desc limit $num,3";
  $query = mysql_query($sql);
  while($info = mysql_fetch_array($query))
  {
  if($j % 4 ==0)
  {
  break;
  }
  ?>
                        <td height="33">
                          <table width="100%" height="150" align="center" cellpadding="0"  cellspacing="0">
                            <tr>
                              <td height="25" align="center" valign="middle"><? echo $info['product_num'];?></td>
                            </tr>
                            <tr>
                              <td align="center" valign="middle"><img src="<? echo $info['product_pic'];?>" width="125" height="100" class="img"></td>
                            </tr>
                        </table></td>
                        <?
       $j++;
     }
   ?>
                      </tr>
                      <?
    }
   ?>