gistfile1.txt

<?php
$installer = $this;
$installer->startSetup();

$installer->getConnection()
    ->addColumn($installer->getTable('sales/quote'), 'surcharge', 'decimal(12,4)');
$installer->getConnection()
    ->addColumn($installer->getTable('sales/order'), 'surcharge', 'decimal(12,4)');

$installer->endSetup();


$setup = new Mage_Sales_Model_Mysql4_Setup('core_setup');
$setup->startSetup();
$setup->addAttribute('quote', 'surcharge', array('type' => 'decimal', 'visible' => false, 'required' => false));
$setup->addAttribute('order', 'surcharge', array('type' => 'decimal', 'visible' => false, 'required' => false));
$setup->addAttribute('invoice', 'surcharge', array('type' => 'decimal', 'visible' => false, 'required' => false));
$setup->addAttribute('creditmemo', 'surcharge', array('type' => 'decimal', 'visible' => false, 'required' => false));
$setup->endSetup();