Give custom Discount on Cart page magento

Give custom Discount on Cart page magento

If you want to give custom Discount in Cart , you have touch below files

app\design\frontend\default\japanese\template\tax\checkout\grandtotal.phtml
japanese_site\app\code\core\Mage\Sales\Model\Quote\Address\Total\Grand.php

in Grand.php in collect function

if($address->getAddressType() == 'shipping')
   {
  $address->setGrandTotal($grandTotal+$totals-100);
   }

That's it... Enjoy Chandresh rana's Coding.... :)