In Drupal we can customize everything, even the search forms. This example show you how to make a custom search block. First you have to make a file named "search-block-form.tpl.php" with this content:
<?php print $search_form; ?>
</div>
even if it isn't different from the one in the core distribution; otherwise the preprocess function isn't executed.
After that you must to open the template.php and use the mechanism of preprocess function to modify template variables before they are passed into the template files.
