display category on home page left navigation in magento

      <?php
/*
* http://fishpig.co.uk - Magento Tutorials
*
* Display top level categories
*
**/
?>
<?php $_helper = Mage::helper('catalog/category') ?>
<?php $_categories = $_helper->getStoreCategories() ?>
<?php $currentCategory = Mage::registry('current_category') ?>
<?php if (count($_categories) > 0): ?>
<div class="block block-layered-nav">
<div class="block-title"> <strong><span><?php echo $this->__('Browse Category') ?></span></strong> </div>
<div class="block-content">
<dl id="narrow-by-list2">
  <dt><?php echo $this->__('Category List') ?></dt>
  <dd>
    <ol>
      <?php foreach($_categories as $_category): ?>
            <li>
                <a href="<?php echo $_helper->getCategoryUrl($_category) ?>">
                    <?php echo $_category->getName() ?>
                </a>
                <?php $_category = Mage::getModel('catalog/category')->load($_category->getId()) ?>
               
                       
                       
                       
                       
                <?php $_subcategories = $_category->getChildrenCategories() ?>
                <?php if (count($_subcategories) > 0): ?>
                  <ol>
                        <?php foreach($_subcategories as $_subcategory): ?>
                            <li>
                                <a href="<?php echo $_helper->getCategoryUrl($_subcategory) ?>">
                                    <?php echo $_subcategory->getName() ?>
                                </a>
                            </li>
                        <?php endforeach; ?>
                   </ol>
                <?php endif; ?>
            </li>
        <?php endforeach; ?>
    </ol>
  </dd>
</dl>
  <script type="text/javascript">decorateDataList('narrow-by-list2')</script>
   </div>
</div>
<?php endif; ?>