(function(onLoad) {
    try {
        window.addEventListener('load', onLoad, false);
    } catch (e) {
        window.attachEvent('onload', onLoad);
    }
})(function() {
  var tags = ["img","input"];
  for( var i=0, len=tags.length; i<len; i++ ) {
    var on = function() { this.src = this.src.replace('_off.', '_on.'); };
    var off  = function() { this.src = this.src.replace('_on.', '_off.'); };
    var el = document.getElementsByTagName(tags[i]);
    for (var j=0, len2=el.length; j<len2; j++) {
      var attr = el[j].getAttribute('src');
      if (!el[j].src.match(/_off\./)&&attr) continue;
      el[j].onmouseover = on;
      el[j].onmouseout  = off;
    }
  }
});