Help me setting the module

Hi,
I installed the module and edit my block.tpl file, than I added the class "myclass" to one block, but in my html code i can't see the myclass class. It doesn't work.

My block.tpl code is:

<div id="block-<?php print $block->module .'-'. $block->delta; ?>" class="clear-block block block-<?php print $block->module ?> <?php print block_class($block); ?>"> 
  <?php if (!empty($block->subject)): ?>
    <h2><?php print $block->subject ?></h2>
  <?php endif;?>

  <div class="content">
    <?php print $block->content ?>
  </div>
  
</div>

and in the form of my block settings I write myclass without quotes.
What is wrong?

Thanks