Explain php function

[Feverh]

I finally got something to work when looping through some returned data from the data base. Can someone please explain exactly how this thing is working? I just want to understand why this worked and nothing else would. I especially would like to know about these portions of script: \[code\]($i % $rewardsPerRow == 0)$i += 1;($i % $rewardsPerRow == $rewardsPerRow - 1) \[/code\]Here is the function\[code\]function displayAvailableRewards() { $sql = db_res("SELECT * FROM `aaa_rewards_list`"); $rewardsPerRow = '3'; $sCode = '<table>'; if (mysql_num_rows($sql) > 0 ) { $i = 0; while ($row = mysql_fetch_array($sql)) { extract($row); if ($i % $rewardsPerRow == 0) { $sCode.= '<tr>'; } $sCode.= '<td width="200" align="center">'; $sCode.= $row['name'].'<br/>'; $sCode.= '<img src="http://www.huddletogether.com/projects/lightbox2/images/image-2.jpg" height="25" width="35" border="0"><br/>'; $sCode.= $row['desc'].'<br/>Points : '. $row['point_value']; $sCode.= '</td>'; if ($i % $rewardsPerRow == $rewardsPerRow - 1) { $sCode.= '</tr>'; } $i += 1; } if ($i % $rewardsPerRow > 0) { $sCode.= '<td colspan="' . ($rewardsPerRow - ($i % $rewardsPerRow)) . '"></td>'; } } else { $sCode.= MsgBox(_t('_rewards_empty_txt')); } $sCode.= '</table>'; $this->addCss('rewards.css'); return $sCode;}\[/code\]