Dimensionality Freebie Example 1

          <div style="position:absolute; left:0px; top:0px; z-index:-100">
<script language="php">
          $rowAbove = array(0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0);
          for ($j = 0; $j < 20; $j++)
          {
            $leftLetter = 0;
            for ($i = 0; $i < 20; $i++)
            {
              $randomLetter = $leftLetter;
              //  generate a random letter a-d not equal to the number to the left or immediately above
              while ($randomLetter == $leftLetter || $randomLetter == $rowAbove[i])
                $randomLetter = rand(97, 100);
              $leftLetter = $randomLetter;
              $rowAbove[$i] = $randomLetter;
              echo "<div style=\"position:absolute; left:", $i*40, "px; top:", $j*40, "px; z-index:-5\">\n";
              echo "<img src=\"rw1", chr($randomLetter), "t40d.png\">\n";
              echo "</div>\n";
            }
          }
</script>
          </div>