You followed a link to a page for version 1 of jScrollPane - the jQuery plugin which provides cross browser custom scrollbars. Version 1 is now deprecated and all development/ support is concentrated on version 2 of the plugin. I suggest that you visit the new jScrollPane homepage to find out all about version 2 of the plugin.
If you must use version 1 of the (for example because you are updating a site that was originally built using version 1) then you can find the old site here.