[Reference article](http://fishpig.co.uk/magento/tutorials/custom-tabs-magento-product-admin/) 

---

Change the above code snippet to this to add a tab in sales order view

```
<?xml version="1.0"?>
 <layout>
    <adminhtml_sales_order_view>
       <reference name="sales_order_tabs">
           <action method="addTab">
               <name>my_custom_tab</name>
               <block>customtabs/adminhtml_sales_order_tab</block>
           </action>
       </reference>
    </adminhtml_sales_order_view>
</layout>

```

and

```
<?php

class Fishpig_Customtabs_Block_Adminhtml_Sales_Order_Tab
extends Mage_Adminhtml_Block_Template
implements Mage_Adminhtml_Block_Widget_Tab_Interface {

```

Important : do change the directory structure