get product max and min price by current category (product Filter ) magento

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get product max and min price by current category (product Filter ) magento
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<?php
 $max_price=Mage::getSingleton('catalog/layer')->setCurrentCategory(Mage::registry('current_category'))->getProductCollection()->getMaxPrice();

 $minPrice=Mage::getSingleton('catalog/layer')->setCurrentCategory(Mage::registry('current_category'))->getProductCollection()->getMinPrice();
?>

$db = Mage::getSingleton('core/resource')->getConnection('core_write');
    $result = $db->query('SELECT max(price) as max_price ,min(price)as min_price FROM catalog_product_index_price ORDER BY customer_group_id');
    $rows = $result->fetch();

    $max_price = $rows['max_price'];
    $min_price = $rows['min_price'];