how to display all child category according to id in magento

php
$cats = Mage::getModel('catalog/category')->load(3)->getChildren();
$catIds = explode(',',$cats);
?>

php foreach($catIds as $catId): ?>
    

        php
            $category = Mage::getModel('catalog/category')->load($catId);
            echo ' . $category->getUrl() . '">';
            echo $category->getName() . '';
        ?>
    

php endforeach; ?>