Load custom block outside magento

load-payment-block-outside-magento.php

<?php
include_once "app/Mage.php";
umask(0);
Mage::app()->loadArea('frontend');

$layout = Mage::getSingleton('core/layout');

//load default xml layout handle and generate blocks
$layout->getUpdate()->load('default');
$layout->generateXml()->generateBlocks();

//get the loaded head and header blocks and output
$headBlock = $layout->getBlock('head');
$headerBlock = $layout->getBlock('header');
$content = $layout->getBlock('content');

echo $headBlock->toHtml() . $headerBlock->toHtml();

echo $content->append( $layout->createBlock('braspag/payment_failure') )->toHtml();
?>