Code related to show category subcategory and their sub subcategory

<div class="inner-page2">

  <div class="col-main">

    <h1><img width="945" height="70"  src="<?php echo $this->getCurrentCategory()->getImageUrl(); ?>"/></h1>

    <div id="fishing-series" class="full-width comman">

      <p> <?php echo $this->getCurrentCategory()->getDescription(); ?></p>

      <?php $base_url=Mage::getUrl()?>

      <?php $this->getCurrentCategory()->getThumbnail(); ?>

      <?php

                        $_category = $this->getCurrentCategory();

                        $collection = Mage::getModel('catalog/category')->getCategories($_category->entity_id);

                        $rootcat = $_category->entity_id;

                        $cat = Mage::getModel('catalog/category')->load($rootcat);

                        $child = $cat->getChildren();

                        $children= json_decode($child);

                        $children=explode(",", $child);

                        $cnt=count($children);

                         $helper = Mage::helper('catalog/category');

                                    $_helper = $this->helper('catalog/output');

                        ?>

      <?php

                                    $_category = $this->getCurrentCategory();

                                    $collection = Mage::getModel('catalog/category')->getCategories($_category->entity_id);

                                    $rootcat = $_category->entity_id;

                                    $cat = Mage::getModel('catalog/category')->load($rootcat);

                                    $child = $cat->getChildren();

                                    if($child)

                                    {

                                                $helper = Mage::helper('catalog/category');

                                                $_helper = $this->helper('catalog/output');

                                    ?>

      <?

                                     $_iterator = 0;

                                       $_columnCount=3;

                                       $_collectionSize=3;

                                       $i=0;

                                     

                                    ?>

      <ul class="product-type">

        <?php      

                                                for($j=0;$j<$cnt;$j++)

                                                {

                                                ?>

        <?php $collection = Mage::getModel('catalog/category')->load($children[$j]); ?>

        <li>

          <div class="products-grid-home12"><a  href="<?php echo $helper->getCategoryUrl($collection);?>"><img  width="215" height="217" src="<?php echo Mage::getBaseUrl('media').'catalog/category/'.$collection->getThumbnail()  ?>" /></a></div>

          <div class="cont"><a  href="<?php echo $helper->getCategoryUrl($collection);?>">

            <?php  echo $collection->getName(); ?>

            </a></div>

        </li>

        <?php

                                                }

                                                ?>

      </ul>

      <?php }

                                                else

                                                { ?>

      <?php echo $this->getProductListHtml() ?>

      <?php

                                                }

                                                ?>

      <div class="clr"></div>

    </div>

  </div>

</div>