(function() {
  // Instantiate and configure YUI Loader:
  var loader = new YAHOO.util.YUILoader({
    base: "",
    require: ["selector","event"],
    loadOptional: false,
    combine: true,
    filter: "MIN",
    allowRollup: true,
    onSuccess: function() {
      registerImageEventHandlers();
    }
  });

  // Load the files using the insert() method.
  loader.insert();
})();

function registerImageEventHandlers() {
  var leftNavImages = YAHOO.util.Selector.query("a img[imageSwap='true']", "leftNavTable" );
  YAHOO.util.Event.addListener(leftNavImages, "mouseover", onMouseOverMenu);
  YAHOO.util.Event.addListener(leftNavImages, "mouseout", onMouseOutMenu);
}

function onMouseOverMenu(event) {
  var target = YAHOO.util.Event.getTarget(event);
  target.src = target.getAttribute("hoverSrc");
}

function onMouseOutMenu(event) {
  var target = YAHOO.util.Event.getTarget(event);
  target.src = target.getAttribute("defaultSrc");
}