Best to stick to one problem at a time. With the frames setup, rename the body frame. The word 'body' should be reserved for the body of a non-frameset page. Call the frame 'main' for example. Now all you need to do is target it with your links. Since you still have not supplied a link to the DD script in question, as requested, I will show you how, generally, to target the 'main' frame with a link:
If the links in the script do not look at all like the above:
<a href="some.htm" target="main">Link Text</a>
Warning: Please include a link to the DD script in question in your post. See this thread for the proper posting format for asking a question.