Question: I have a table `Purchaseforms` with some fields. This table has two fields `PurchaseId` which is an identity and `PurchaseNumber` which is an `nvarchar`.

After inserting a row in Purchaseform table, it returns `@@IDENTITY`. I want to update the PurchaseNumber field after insert immediately.

E.g.

If the `PurchaseId` is 1000, `PurchaseNumber` should be updated to `P1000`. How can I do it?

Answer: 
To change the shipping methods title of **USPS** methods just go to this file `app\code\core\Mage\Usa\Model\Shipping\Carrier\Usps.php` and in `getCode()` function you will find various title of **USPS** shipping methods from here you can change title.
Refer below link. using you can do your requirement. i also done.

<http://www.magentocommerce.com/magento-connect/webshopapps-matrixrate-1-multiple-table-rates-extension-certified-bug-free.html>

from this module you can upload CSV file for store view wise.