Magento按字母顺序输出类别和子类别

我有代码按ID在magento中输出类别，但希望这些结果按字母顺序输出。谁能提出什么建议？

 <?php 
$parentCategoryId = 201;
$cat = Mage::getModel('catalog/category')->load($parentCategoryId);
$subcats = $cat->getChildren();
// Get 1 Level sub category of Parent category
foreach(explode(',',$subcats) as $subCatid)
              {
                $_category = Mage::getModel('catalog/category')->load($subCatid);
  if($_category->getIsActive()) {
     echo '<li><a href="'.$_category->getURL().'" title="View the products for the "'.$_category->getName().'" category">'.$_category->getName().'</a>';
   echo '</li>';
  }
}
?>