How to get sub category list for specific category in magento

Below is the code to get sub categories list from specific category in magento. For example, if we make a category by name “brand” (fro example id is 35) and we want to show all the subcategory list as select dropdown. So we can use below code :

<select id="select-manufacturer" style="font-size: 11px;" onchange="window.location.href=this.value">
<option selected="selected" value="#">----Select Brand----</option>
<?php $_category = $this->getCurrentCategory();
$collection = Mage::getModel('catalog/category')->getCategories(35);
$helper = Mage::helper('catalog/category');
?>
<?php foreach ($collection as $cat):?>
<?php if($_category-&gt;getIsActive()):?>
<?php $cur_category = Mage::getModel('catalog/category')->load($cat-&gt;getId());
$_img = $cur_category->getImageUrl();
?>
<option value="<?php echo $helper->getCategoryUrl($cat);?>">
<?php echo $cat->getName();?>
</option>
<?php endif?>
<?php endforeach;?>

</select>