OSCommerce integration problem

I been helping out a small businesses who has experienced problems concerning ebay / paypal integration into their existing sites using oscommerce

the problem revolved around his site that use frames and pay pal's insistence relating to security issues, more so compatibility

This is how it would look if making it appear within the same window:

the first problem was getting paypal to work in frames thus opening in a new window, below shows what to do

in catalog/checkout_confirmation.php, around line 123, find this code: echo tep_draw_form('checkout_confirmation', $form_action_url, 'post');

replace with the following: echo tep_draw_form('checkout_confirmation', $form_action_url, 'post', 'target="_parent"');

editing the above code should solve the problem of a website using frames

thanks to neil from http://www.neildavison.co.uk for allowing me to publicise this problem