This demonstration shows how you can apply jScrollPane to content in an iframe. Note that in this demo nothing is done in the hosting page (this one), all of the necessary javascript happens inside the loaded pages (e.g. iframe_content1.html and iframe_content2.html). Those pages basically use the same technique as in the full page scroll example.
To implement this technique you don't need to add any code to the hosting page but you do need to have control over the pages which you load into the iframes. And each of those pages will need to include the relevant script files (e.g. jQuery, jScrollPane etc etc) as well as the document ready script as I show in my examples.
The contents of this div will be replaced by the javascript added to this page
The contents of this div will be replaced by the CSS added to this page