Magento show subcategories of current category

subcategories.phtml

<?php
$_categoryModel = Mage::getSingleton('catalog/layer')->getCurrentCategory();

$_categories = $_categoryModel->getCollection()
        ->addAttributeToSelect(array('name', 'thumbnail', 'image', 'description',))
        ->addAttributeToFilter('is_active', 1)
        ->addIdFilter($_categoryModel->getChildren())
;
if(empty($_categories)){
	return;
}

$_span = 'span4';
$_grid_pro = Mage::getStoreConfig('themeoptions/themeoptions_config/grid_product');
if ( !$_grid_pro ) { $_grid_pro = 3; }
switch ($_grid_pro)
{
case 2:
	$_span = 'span6';
	break;
case 3:
	$_span = 'span4';
	break;
case 4:
	$_span = 'span3';
	break;
}

$_collectionSize = $_categories->count();
$_columnCount = $_grid_pro; //$this->getColumnCount();


?>
<?php $i=0; foreach ($_categories as $_category): ?>
	<?php if ($i++%$_columnCount==0): ?>
	<div class="products-grid row-fluid">
	<?php endif ?>
		<div class="<?php echo $_span ?> item<?php if(($i-1)%$_columnCount==0): ?> first<?php elseif($i%$_columnCount==0): ?> last<?php endif; ?>">
			<div class="item-inner">
				<?php if($_category->getThumbnail()):?>
					<a href="<?php echo $_category->getUrl() ?>" title="<?php echo $this->stripTags($_category->getName(), null, true) ?>" class="product-image">
						<img src="<?php 
							echo Mage::getBaseUrl('media') . 'catalog' . DS . 'category' . DS . $_category->getThumbnail() ?>" alt="<?php echo $this->htmlEscape($_category->getName()) 
						?>" /></a>
				<?php endif; ?>
				<div class="product-item-info">
					<h2 class="product-name"><a href="<?php echo $_category->getUrl() ?>" title="<?php echo $this->stripTags($_category->getName(), null, true) ?>"><?php echo $_category->getName(); ?></a></h2>
					<p><?php
						echo Mage::helper('core/string')->truncate(
							$this->stripTags(
								preg_replace('/<h[0-9][^>]*>([\s\S]*?)<\/h[0-9][^>]*>/', '', $_category->getDescription())
							), 
							200
						);
					?></p> 
					<div class="actions">
						<a href="<?php echo $_category->getUrl() ?>" class="button"><span><span>Detalhes</span></span></a>
					</div>
				</div>           
			</div>
		</div>
	<?php if ($i%$_columnCount==0 || $i==$_collectionSize): ?>
	</div>
	<?php endif ?>
<?php endforeach ?>
<script type="text/javascript">decorateGeneric($$('ul.products-grid'), ['odd','even','first','last'])</script>