livedoor reader - key change

ldr_key.user.js

// ==UserScript==
// @name           ldr_key
// @namespace      basyura.org
// @include        http://reader.livedoor.com/reader/*
// ==/UserScript==

(function(){
  var w = unsafeWindow;
  var _onload = w.onload;
  var onload = function() { with(w) {
      Keybind.add("j" , function() {
          var container = document.getElementById("right_container");
          if (container.scrollTop == 0) {
            Control.scroll_next_item();
          }
          else {
            Control.scroll_next_page();
          }
        });
      Keybind.add("k" , Control.scroll_prev_page);
      Keybind.add("d" , Control.scroll_next_item);
    }}
  w.onload = function(){
    _onload();
    onload();
  }
})();