/**
 * Onload function
 */
Event.observe(window, 'load', function() {
  $$(".active_image").each(function(elem) {
    elem.setStyle({ cursor : 'pointer' });

    if (!Prototype.Browser.IE) {
        elem.observe('mouseover', function(evt) {
          activateImage($(evt.target));
        });

        elem.observe('mouseout', function(evt) {
          deactivateImage($(evt.target));
        });
    }
  });
  
  $$(".select_on_focus").each(function(elem) {
    elem.observe("focus", function() { elem.select(); });
  });
});

function activateImage(img) {
  var src = img.src;
  var dot = src.lastIndexOf(".");
  var image = src.substring(0, dot);
  var extension = src.substring(dot);
  
  if (image.toLowerCase().indexOf("_on") < 0) {
    img.src = image + "_on" + extension;
  }
}

function deactivateImage(img) {
  var src = img.src;
  var dot = src.lastIndexOf(".");
  var image = src.substring(0, dot);
  var extension = src.substring(dot);
  
  if (image.toLowerCase().indexOf("_on") > 0) {
    img.src = image.substring(0, image.length - 3) + extension;
  }
}