magento 1.5:Add a new field in catalog_manage product_add product_continue_custom options in product options container?

i want to add a new text field as stock in catalog->manage products->add product->continue->custom options-> in add new options container just after sort or开发者_C百科der text field.I am trying for a week but i am not getting the template where i have to add the new field.If there is any other way to add the new field please help me....

Add a new field in catalog_mange product_custum options.

Files:

1. C:\xampp\htdocs\magento\app\design\adminhtml\default\default\template\catalog\product\edit\options\option.phtml
2. C:\xampp\htdocs\magento\app\design\adminhtml\default\default\template\catalog\product\edit\options\type\text.phtml
3. C:\xampp\htdocs\magento\app\design\adminhtml\default\default\template\catalog\product\edit\options\type\select.phtml
4. C:\xampp\htdocs\magento\app\design\adminhtml\default\default\template\catalog\product\edit\options\type\file.phtml
5. C:\xampp\htdocs\magento\app\design\adminhtml\default\default\template\catalog\product\edit\options\type\file.phtml
6. C:\xampp\htdocs\magento\app\code\core\Mage\Adminhtml\Block\Catalog\Product\Edit\Tab\Options\option.php

Tables:

1. catalog_product_option; Add a new column named ‘stock’ manually in this table............
2. catalog_product_option_price
3. catalog_product_option_title
4. catalog_product_option_type_price
5. catalog_product_option_type_title
6. catalog_product_option_type_value; Add a new column named ‘stock’ manually in this table............

For such detailed purposes one better should use combined products instead of product custom options.