Help with shortening a snippet of code

[Frederick]

I have the following code that will display items across by the specified amount and then begin a new row.
What I am looking for is a method so I can have it dynamicly create instead of adding a new if($rowcnt == 24) { echo "<tr>"; } to insure there is enough incase a person wants to display 60 images per page.
Why they would? I don't know why.

$rowcnt = 0;
// sql and while begin loop here

if ($rowcnt == 0) { echo "<tr>"; } if ($rowcnt == 4) { echo "<tr>"; } if ($rowcnt == 8) { echo "<tr>"; } if ($rowcnt == 12) { echo "<tr>"; }
if ($rowcnt == 16) { echo "<tr>"; } if ($rowcnt == 20) { echo "<tr>"; } if ($rowcnt == 24) { echo "<tr>"; } if ($rowcnt == 28) { echo "<tr>"; }
if ($rowcnt == 32) { echo "<tr>"; } if ($rowcnt == 36) { echo "<tr>"; } if ($rowcnt == 40) { echo "<tr>"; } if ($rowcnt == 44) { echo "<tr>"; }
if ($rowcnt == 48) { echo "<tr>"; } if ($rowcnt == 52) { echo "<tr>"; } if ($rowcnt == 56) { echo "<tr>"; } if ($rowcnt == 60) { echo "<tr>"; }

$rowcnt = $rowcnt + 1;
// while loop ends here

This is what it does: http://206.124.138.203/gallery/index.php?page=thumbs&catID=1

[bastien]

use the mod function

$rowcnt =@$_POST['rowcount'];

if ($counter % $rowcount == 0){

echo "</tr><tr>";
}// endif

where $counter is the incremental element in the result set