// Change every link in the document matching PREDICATE to open in a
// new window.
function make_links_target_new_window (predicate)
{
  var atags = document.getElementsByTagName ('a');
  for (var idx = 0; idx < atags.length; ++idx)
    {
      if (predicate (atags[idx]))
	atags[idx].target = '_blank';
    }
}

add_normal_handler
  (window, 'load', function ()
   {
     make_links_target_new_window
       (function (link) {return 0 <= link.href.search (/\.pdf$/i);});
   });