Magento Provides the manage customers feature to list and edit the customers information.
The Customer edit page in the admin panel gives details about the customers account information,address,orders etc.
In some scenarios we may need to show our custom module contents related to the customer in a additional tab. To achieve this functionality we need to create a custom module and add our tab.
Step 1: We start with our config.xml file. In this file we are specifying an adminhtml xml layout file and a Block class for our custom module.
app/code/local/Mydons/etc/config.xml



